I have a 101 on approval and it sounds dire. The bass is monotone, thudding and exaggerated, the midrange is slightly muffled and the treble dull. I have tested it with both Avondale and Naim power amps and the sound was basically the same. The guy I borrowed it from said this is normal, as they only work properly with Meridian power amps. Is this the case? I had a quick look inside and it all looks original, I guess it could just need a recap/service? The sound is the same irrespective of source or input.

It looks like this:
http://www.doebbe.com/hifi/pics/Meridian_101_ret_3s.jpg

But has the original axial smoothing caps. Any decent 100 series links or information about alternative modules would also be appreciated.

Regards,

Mus

This is what mine looks like
http://www.hsdhick.f2s.com/101.jpg

Thanks, yours looks a lot neater, is it a 101 or a 101B? What are the three modules in yours? Which power-amp do you use?

Regards,

Mus

Hi Mus,
cobbers just beat me to it, I was going to upload mine which, before mods, looked the same as his.
The difference is that ours are earlier discrete versions whilst your pic is the later op-amp version.
I think I am correct in this but MarkS who helped me a lot could confirm.
There is an earlier thread with some info.
http://www.pinkfishmedia.net/forum/showthread.php?t=32838&highlight=meridian+101
I found that they are a little bass heavy but I have fitted ALW Sregs to mine and find it a pretty perfect match to the Exposure IV and Bariks. As I noted after the Sreg mod the bass disappeared but it came back tight after 12 hours initial warm up
I only use CD so I have removed the cartridge modules.
http://homepage.ntlworld.com/john.baldam/dogrun.gif

I have a 101 on approval and it sounds dire.

Thats a 101b with, I think, a non original set of caps in the psu.

Pm me your email & I'll send you the cct diag so you can check it out.

Hi J&J

Thanks for the information, I did read your thread, very interesting. Am I right in thinking the 101 has +15V and -15V rails, did you use only +15V superregs? Where did you break into the circuit to insert your superregs?

Regards,

Mus

The guy I borrowed it from said this is normal, as they only work properly with Meridian power amps. Is this the case?

ermm...the word bollocks comes to mind...

101 preamp output impedance usually 600 ohms, unless 75ohm output module fitted.

103/105/105s power amp input impedance 11k.

Thats a 101b with, I think, a non original set of caps in the psu.

Pm me your email & I'll send you the cct diag so you can check it out.

Thanks, PM sent. The picture is not the one I have but near enough, on closer inspection it looks like the PSU caps have been bypassed.


ermm...the word bollocks comes to mind...



Yep, to my mind too.

Regards,

Mus

Hi Mus
That's how it was when I got it,have since replaced all radial electrolytics with Panasonic FC's and the axials with Vishay's (there were some leaking-you can just about see the stain on the PCB under the 100mfd by the side of the transformer).
It's used as a preamp for a Chiara headphone amp as living where I do all proper listening is done on headphones and the balance is far from how you describe yours,the bass is tight and tuneful with plenty of midrange detail and good treble extension-possibly a little bright but not uncomfortable.
The 3 modules are the input gain stage for a Supex,the RIAA equalisation stage and output stage (cartridge is an ATF5 OCC)
All I need now is a MM input-anyone got one going?

All I need now is a MM input-anyone got one going?

Pm me your email & I'll send you the correct conversion info for all (mc & mm)cartridge combinations.

This is what mine looks like


This is the original discrete 101...the best, imho.

Hi J&J

Thanks for the information, I did read your thread, very interesting. Am I right in thinking the 101 has +15V and -15V rails, did you use only +15V superregs? Where did you break into the circuit to insert your superregs?

Regards,

Mus

HiMus,
Yes 15v pos 15v neg. I used neg and pos Sregshttp://homepage.ntlworld.com/john.baldam/sregs.JPG
I've shortened all wires since this to tidy it up a little.
If you turn the board upside down and remove the regs, the tracks leading from the rectifier are easy to see to solder the inputs to and the old output from the regs are easy to see to solder the new outs to. I joined in and out grounds together and soldered to the old ground track.
It all makes sense with MarkS's diagram with the board in front of you.
It is a very good mod, until I did it I thought the 101 would not fit in my system.

http://homepage.ntlworld.com/john.baldam/dogrun.gif

Hi Mus,
the pic in your post is it the one you have as It looks like this one
http://www.doebbe.com/hifi/items/meridian101.html
which is where I first looked for info.
http://homepage.ntlworld.com/john.baldam/dogrun.gif

Have a word with Les,he used to modify these fine little pre-amps in days of old,i dont think he works on them any more but i'm sure he would point you in the right direction re- "tweaking"!!

Hi Mus,

Is the Meridian for tweaking then?

We need to get the Densen & Dynavector across to you to try out..

Regards,

Kev

hi Mus,
have you been here
http://www.pinkfishmedia.net/forum/showthread.php?t=32455&highlight=meridian+101

http://homepage.ntlworld.com/john.baldam/dogrun.gif

Is the Meridian for tweaking then?
Hi Kevin,

It was originally for a friend, but after a bit of research - and having seen how small they are - I'm interested too. I don't imagine it will escape the attentions of my soldering iron though.

We need to get the Densen & Dynavector across to you to try out..

You have an open invite and a rather nice Balti house just opened down the road.

Regards,

Mus

The guy I borrowed it from said this is normal, as they only work properly with Meridian power amps. Is this the case? I had a quick look inside and it all looks original, I guess it could just need a recap/service? http://www.doebbe.com/hifi/pics/Meridian_101_ret_3s.jpg




Hi Mus,

The original owner is talking tosh.
The 101 is a decent pre amp, especially if you run the phono stage.
Replace any tired old electrolytics and it'll sound great. I've yet to hear any circuit not benefit from SRs but you might find Avondale TPR boards better in this situatuion as they are roughly half the size of a SR with no bulky components on the board. I just built a PSU for my NAT101 tuner using one and I'll post a pic later to give you some idea.

Hi Rob,

Thanks, I forgot about the TPRs, I have a pair built I could have a play with.

The owner wants £50 for the 101 - sold as seen - but that includes a MM and a MC module. The case is in average condition, the controls are smooth and crackle free and it seems to work - other that the sound issues. I guess it might be worth having a punt at that sort of price?

Regards,

Mus

Hi Mus,
I bought mine off Ebay for £50 on a buy it now, they have recently been going for more.


http://homepage.ntlworld.com/john.baldam/dogrun.gif

Shhhhhhh, don't tell everyone! :) I was watching that one but I have never seen a black 101 in the flesh. My main concern is that the black finish is supposed to be a lot less durable than the classic brown finish. Given that many brown ones are looking tatty I dread to think what the black ones are like. The only consolation is that the black paint will be easier to match.

Regards,

Mus

Mus, PM me your email and I'll email you some pics of the internals of my 2 101s and one of my 101Bs. Somethings not right here IMHO. The 101 and 101B are both super amps and at the prices they go for something af a HiFi bargain. And yes they do work perfectly well with other power amps.

Is this one really be a 101 - it's shown with a B IMCOS module - which is a complete mismatch. So the phone would sound like sh*t for sure. Neil

Mus,

the internals of the 101 and 101B can be seen here respectively:

101: http://i26.photobucket.com/albums/c114/neiljadman/Meridian%20101/101.jpg

101B: http://i26.photobucket.com/albums/c114/neiljadman/Meridian%20101/101b.jpg

Note the extra cable for the balanced output running from the output module to the din output socket.

These are both US spec units. My UK unit (101B) differs only in that the toroidal transformer is smaller and enclosed in a square metal can that screws down on to the chassis. Unfortunately I don;t have it with me to take any pics. The US transformer is larger in diameter!

Neil

Is this one really be a 101 - it's shown with a B IMCOS module - which is a complete mismatch. So the phone would sound like sh*t for sure. Neil

As I said before this is a 101b. The srbp motherboard as opossed to fr4 for the earlier 101's. Someone buggered around with the psu caps, thats what makes it look odd.

Btw, the black ones, whilst looking cool, are opamp based.

I stripped the PCB out and discovered a few dry joints around the PSU. After removing the old solder, I re-soldered the joints and things improved tremendously. That said, it was still sounding a bit odd so I took the crappy looking flying leads apart and discovered a dogs dinner. Really bad lumpy soldering, no insulation, and two of the pins were nearly shorting. I re-terminated the leads and the 101 is now playing music.

I have some quality DIN plugs in my spares bin but they won't fit through the hole in the 101s chassis because of a lip. What DIN plugs do you guys use, can you get quality DIN plugs without the lip? Failing that I might make up some phono cables and hard wire them to the PCB like the phono connector.

Thanks for all the advice and pictures.

Regards,

Mus

Mark, surely the one shown in the link in Mus' first post is a 101? All the original pics are here: http://www.doebbe.com/hifi/items/meridian101.html and I'm pretty sure that's a 101 not a B - despite the IMCOS module.

Now if Mus' has the flying leads it's somewhat different from the one in the link above and is a B.

Anyway, glad to hear the Mus is reviving it!

Hi Mus
Got my 5 pin from Farnell they are Deltron 1193813 with silver plated pins.
They fit fine (and the 7 pin equivalent)
Glad to hear you are getting somewhere with it!

101B: http://i26.photobucket.com/albums/c114/neiljadman/Meridian%20101/101b.jpg


That is a later, op amp based 101 with original discrete input & eq modules instead of the imcos. You can see the ne5532 opamp for the radio input stage on the lhs together with the phono lead inputs instead of the original 5 pin din.

Hi Mus
Got my 5 pin from Farnell they are Deltron 1193813 with silver plated pins.
They fit fine (and the 7 pin equivalent)
Glad to hear you are getting somewhere with it!

Nice one, thank you.

Regards,

Mus

Sorry for the confusion guys, the picture I posted looks like mine but is not exactly the same. Mine has two rectangular modules similar in size to the picture I posted, it also has flying leads for the phono. The phono/RIAA module clearly states "For 101B only" and there are op-amps dotted around.

Regards,

Mus

Well that 101B on ebay sold for £127.94 !!!!!!!
Got my original for £46 ,amazing what a box will do!!!!
http://cgi.ebay.co.uk/Meridian-101-Pre-Amp-MC-Module-Boothroyd-Stuart_W0QQitemZ140099457148QQcategoryZ12050QQssPa geNameZWDVWQQrdZ1QQcmdZViewItem

Well that 101B on ebay sold for £127.94 !!!!!!!
Got my original for £46 ,amazing what a box will do!!!!
http://cgi.ebay.co.uk/Meridian-101-Pre-Amp-MC-Module-Boothroyd-Stuart_W0QQitemZ140099457148QQcategoryZ12050QQssPa geNameZWDVWQQrdZ1QQcmdZViewItem

Yeh I was stunned too - makes my little collection look better and better every day:

2 x 101
2x 101B
6x 105s
2x 104
1x 103
1x 103D
and a spare 103 power amp needing a power supply - all with original boxes and many with literature.

I also have a real oddity - a Meridian tape switching unit, built and supplied by Meridian to allow tape-tape dubbing and use of 2 tape decks: http://i26.photobucket.com/albums/c114/neiljadman/MeridianMCStepUpRr.jpg and http://i26.photobucket.com/albums/c114/neiljadman/MeridianMCStepUpFr.jpg

Ah! anoraks convention

2 x 101
3 x 101b
1 x 104
6 x 105s
1 x 103(d)
1 x pair M2
1 x pair M3
1 x pair M60

also, awaiting delivery of Lecson pre+power(AP3)

Hi MarkS
I see there is a Supex module on epay at the moment - would be ideal if I could have both MC and MM so I can swap cartridges as I used to but then christ knows what that will go for now.Just hope my epay alterego i------------i can afford it!

Hi MarkS
I see there is a Supex module on epay at the moment - would be ideal if I could have both MC and MM so I can swap cartridges as I used to but then christ knows what that will go for now.Just hope my epay alterego i------------i can afford it!

If your 101 has an imcos module you will also require the riaa eq module to go with the supex one. The imcos is in effect a dual module box.

Hi MarkS
I've got the original 3 box setup-can't I just swap the input gain stage and leave the RIAA as is?:confused:

Hi MarkS
I've got the original 3 box setup-can't I just swap the input gain stage and leave the RIAA as is?:confused:

Correct :D

Well landed meself a spare Supex module and converted it to MM 47k to drawing except the 100pF caps has been exchanged for a 220pF polystyrene which I had in stock ,fortunately my phono leads are short and only about 70pF per metre so should be no problem.
Amazed to see the number of modules on Ebay lately - all from the same seller!

Hi

I am starting to refurbish my 101 / 103 setup.

Just replaced the stock 6800uF 63v ITT by some two 15000uF 63v mundorf in the 103 PSU.

Big improvements in bass detail for now... must wait to report after running in the caps.

Great thread..;)

Regards

Ricardo

Big improvements in bass detail for now... must wait to report after running in the caps.

Ricardo, try powering the 103 direct and not through the Preamp if you didn't already - you might just be surprised.

Neil

Ricardo, try powering the 103 direct and not through the Preamp if you didn't already - you might just be surprised.


Thank you Neil

You gave me will to power the 103 directly to the mains. I must source a high quality switch for power and will use a special power cord.

Regards

Ricardo

Ricardo, try powering the 103 direct and not through the Preamp if you didn't already - you might just be surprised.

Hi Neil

Just did it !

Now I have a separate switch just to power the 103 separatedly from the pre101.

The new switch is built in a separated case with a IEC inlet so I can use a special cable (Supra 2.5mm2 in this case).

Even 30 minutes after the modd, the benefits are awesome.... Much better dynamics, better bass detail, less distortion under power and much better headroom.

I am really surprised...:D

Thank you for your suggestion.

Best regards

Ricardo

I could never believe the iffy reviews the 101/103 series had in HiFi Choice at the time. We loved them and it was only the acquisition of Naim in 1977 that sort of took out attention away from this brand. The Imcos module in the pre didn't help either, as all the air and space seemed to disappear. The 107 power amp was great too if you can find one and re-furbish it. I'd be interested to know if the 105's can sound less harsh these days with bigger supply caps of the same physical size and maybe other tweaks.

Is the general concensus that the 101b is better again than the early 101's? I heard one several years later and thought it very good. I also really liked the M20's that they were demming at a local show in 1985, where I collected my MCD-Pro, which is still around...

Is the general concensus that the 101b is better again than the early 101's? I heard one several years later and thought it very good. I also really liked the M20's that they were demming at a local show in 1985, where I collected my MCD-Pro, which is still around...
The first "proper" hifi I heard belonged to the father of an old g/f. He had an LP12/Alphason (can't remember the cartridge) running into a 101/M20's. Sounded pretty good to me. I understand it's still going strong some 20 odd years later.

My first CD player was an MCD which I sent back to the factory to be "pro'd" when they offered that upgrade. Both spanked by my Planar 3/P77 as I recall but fun to watch them "hunt" down a track towards then end of a CD. It could take a good 15 seconds to scan to the track. Anyone still got one of those MCD Pro "floppy mat" things? I used that to good effect on a number of later CD players. Unfortunately I lost it before I got my CDS2.

Duncan

Min old MCD-Pro is still complete with mat and I think the owner has the boxes too. It's suffering a bit now - don't know if it's the laser gone or a bad internal connection, as I had crackling coming from poor continuity in the internal DIN plug and socket connecting the two boxes together.

The CDS2, according to Dave, seems immune to different generations of pucks and things and the XPS power supply is certainly more mains proof than the amps used to be. Bearing in mind the blackout paint in the CD compartment and fine suspension etc., I suspect the mat wouldn't make any difference, to be honest. The level of sound given by this player also is rather above tweakery IMO too...;)

...The 107 power amp was great too if you can find one and re-furbish it...

Now that would be a great find. IIRC only about 8 or 9 were ever built under the Meridian label, it being a re-badged crossover from the short lived Orpheus era.

Thats a 101b with, I think, a non original set of caps in the psu.

Pm me your email & I'll send you the cct diag so you can check it out.

Hi Mark

Just read all the thread and can not stop thinking about my soldering iron.

My 101 sounds very good but needs a recaping.

I also own a MC module that I would like to modify to suit my Benz ACE.

Can you provide some information ?

Regards

Ricardo

Just joined the 100s series club with a 101 and a 103d combo. Noticed that the recommendation appears to be to power the PSU direct from the mains, is this just a case of plugging the power lead into an ICE lead? ok appreciate that rewiring might be better but this approach does keep them orginal

Secondly the 101 has Supex module in the plan would be to use a high quality step up transformer between a Koetsu and the Supex MM - did Meridian ever make a Koetsu module and if so is it likely to be worth while looking out for one. The modules seem pretty firmly in place are they soldered in or just push fit, Ditto the black covers seem pretty tight on and I guess a little brittle these days - is it best to leave alone.

The inside looks pretty much like one of the earlier discrete version picture post is there an easy way to tell without looking inside the output module?

Think I see now

lots of components on the board between the phono box and the inputs at the rear = discrete :)

http://www.hifiengine.com/gallery/meridian-101.shtml
3 separate modules = discrete
http://www.doebbe.com/hifi/items/meridian101.html
above = IC

This brings back so many good memories, especially of the original three-module 101 with 103d amp. Worked so well with Harbeth HL's and Tangent RS4's IIRC.

May thanks I was obviously over complicating matters - it has 3 black modules.

any idea on

if the modules pull out push in or are soldered in place and removal of the black covers.

and runni
ng 103s direct of mains ? just plug the existing plug into an ICE lead ?

The modules could be carefully pulled out and different ones inserted. The amp can be plugged directly into the mains via a good quality IEC lead. I would recommend not leaving it powered 24/7 though, as it is thirty years old...

By the way, Bob Stuart told us that beefing up the preamp's power supply was unnecessary in this circuit as it works differently to the Naim one for example.

Actually having looked at the 101 a bit closer the shell with the Serial Number has a sticker which says Supex but the phono module says moving magnet so guess my supex comment above was bit misleading -sorry

Don't forget the Supex 901, which was a high output mc.....

When I first looked at the pre it had a label on the outside case that said Supex which made more sense for it to be a high out put MC but inside the module says Moving Magnet on a a 1977 date stamp so I guess the module was swapped at some point.

I am sure I read somewhere that the Koetsu and Supex actually work best into a MC input via a step up so I will try the Koetsu direct in the first place and see what happens if no volume I will put the step up in series. Never used a MC input !

Just joined the 100s series club with a 101 and a 103d combo. Noticed that the recommendation appears to be to power the PSU direct from the mains, is this just a case of plugging the power lead into an ICE lead? ok appreciate that rewiring might be better but this approach does keep them orginal

The inside looks pretty much like one of the earlier discrete version picture post is there an easy way to tell without looking inside the output module?

Hi

Enourmous benefits come from powering the 103 psu directly to the mains.

Gently lift the output module and look underside.

Search for 8 pin aligments in the middle... if so, than your´s is using a opamp in the output.

Look here for details: http://www.diyaudio.com/forums/showthread.php?postid=1657603#post1657603

Regards

Ricardo

PS: Recaping the 101b was really revealing.... This is a high end preamp !

When I first looked at the pre it had a label on the outside case that said Supex which made more sense for it to be a high out put MC but inside the module says Moving Magnet on a a 1977 date stamp so I guess the module was swapped at some point.

I am sure I read somewhere that the Koetsu and Supex actually work best into a MC input via a step up so I will try the Koetsu direct in the first place and see what happens if no volume I will put the step up in series. Never used a MC input !

The high output Supex 901 works into a MM input, so the label might be correct.

The Koetsu is a low output MC and needs a x'mer step up into the MM input or a dedicated MC input.

I am using a high output Benz ACE with wondefull results in my MM input. (I replaced the 47kr loading by a 39kr tantalum and removed the 120p cap. Also replaced the 100uF Tant coupling between head amp and RIAA eq by a 100uF BGNx with enourmous gains in detail.

Hope this is not way off topic but I believe these machines really like good updated components.

Ricardo

The high output Supex 901 works into a MM input, so the label might be correct.

The Koetsu is a low output MC and needs a x'mer step up into the MM input or a dedicated MC input.


Many thanks Dave

Hi

Search for 8 pin aligments in the middle... if so, than your´s is using a opamp in the output.

Look here for details: http://www.diyaudio.com/forums/showthread.php?postid=1657603#post1657603

Regards

Ricardo


Hi Ricardo

Had a look at the post suggested and also the picture at

http://www.diyaudio.com/forums/attachment.php?postid=1709927&stamp=1231714862

My output stage looks much more akin to the phone input and RIAA stages in your first post so fingers crossed

Ian

Hi Ian

Did you remove the output stage ? (It comes off easily just by pulling up due to the gold contacts)

Mine is "naked" because I needed to remove the cover to recap and replace the opamp.
Previously it just looked like the other two (In the pic, only the Riaa eq is covered)

After recaping and replacing the opamp by one of the new "metal can", the pre was lifted to high end status.

Ricardo

Ola Ricardo

Yes I gentled eased all three off once I knew they came off it was very straightforward all amps should be built like this !

as far as I can tell from the solder and pins below all the modules look discrete. ( The pins don't appear to match to the parts in your "naked module" on the later post much more like the bottoms of the 2 phono modules in the earlier post)

I did take some pictures but cant see an easy way to post on here.

I did a gradual power up the other day after checking there was no obvious faults but haven't got past an all working test with some old speakers. Had a worry at first when one channel wasn't working but traced it down to a din to rca phono lead that had the wrong pins wired.

I might manage to get it in system next week end and have a proper listen.

So probably yours has a discrete output. It is precious !

Do you know if it has ever been serviced ?

Regards


Ricardo

Hi Ricardo

No idea on the pre - I suspect not as it all looks very original.

The 103 Power amp looks as if it has work done on it at some point. Very neat very tidy but some components are different makes on the different channels. resistors included but the values look the same.

the 2 PSU look original.

I am doing my best not to mod but keep as they are - might not be the best route for sound quality but unless they sound dire it is probably best longer term

Hi Ian

The power cord mod on the power amp psu is very important... better transients, better bass, better dynamics.

Can you please post some pics of the inside of the power amp ?

Regards

Ricardo

Hi Ricardo

The pre looks identical to the picture Cobbers posted but mine has a red spot MM phono stage.

I have used my last bit of thermal paste to stick the heat sink to the case on the power amp so dont fancy taking it apart right now unless its urgent. The PSU are basically 2 big blue caps plus a transformer will post later if it helps

Can I post pictures here without hosting them elsewhere ? if so how ?

Ian

http://i665.photobucket.com/albums/vv15/Mr_Ian/OutputStage.jpg

http://i665.photobucket.com/albums/vv15/Mr_Ian/PhonoEqualisation.jpg

http://i665.photobucket.com/albums/vv15/Mr_Ian/MMModule.jpg

Just found the pictures I took when I had the cases off - forgot where i had put them>

PSU
http://i665.photobucket.com/albums/vv15/Mr_Ian/DSC00151.jpg

Power Amp
http://i665.photobucket.com/albums/vv15/Mr_Ian/DSC00150.jpg

Pre Amp
http://i665.photobucket.com/albums/vv15/Mr_Ian/DSC00149.jpg

Did you plan to repalce those big blue ITT caps? I would if I were you, I've seen too many like this: http://i26.photobucket.com/albums/c114/neiljadman/BadCap.jpg

Cornell Dubeliers make excellent replacements.

I've just recently examined my PSU caps and they are bulging and leaking. They are 1979 originals though, I'm just surprised/disappointed Meridian didn't replace them when one went for repair in 2004.

Hi Neil

Thanks for that

I expected to see some bulging and leaking but all looks ok right now,

I noticed that some one had replaced the ITT 6800 with Munford 15,000UF 63v
any other views on keep or replace and if so replace with what.

It would be nice to find some more ITT - if they have lasted 30 years ..... and it keeps things original

Cornell Dubeliers make excellent replacements.

Found some CDE on Farnell at GBP50 each, I thought they would be about a tenner.

Found some CDE on Farnell at GBP50 each, I thought they would be about a tenner.

Ouch - that hurts. No need to spend that much. This is what I used last: CDE 10,000uF (http://mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMsCnlYck6hSqLhQjFWS HEDhXoVMqRVeJ1I%3d). But they are smaller and you need to rig the fitting.

found these too which appear well regarded

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=3819093

also if I drop the screw terminals and go with a PCB mount I think I have found a good price but not sure if the saving will be worth the pain of trying to wire the pins

The solder tag type will be an easier drop in, and upping it to a 10,000uf helps too:BHC Solder tag caps (http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=3397931)

Just found the pictures I took when I had the cases off - forgot where i had put them>

PSU
http://i665.photobucket.com/albums/vv15/Mr_Ian/DSC00151.jpg

Power Amp
http://i665.photobucket.com/albums/vv15/Mr_Ian/DSC00150.jpg

Pre Amp
http://i665.photobucket.com/albums/vv15/Mr_Ian/DSC00149.jpg

Hi Ian
I replaced the stock ITT 6800uF for Mundorf 15000uF because the blue ones were bulging due to the age.

Regarding the preamp, you should consider replacing the post regulator caps (ITT) by some 680uF 35V BG Nx that fit nicely there and really boosted the performance.

The power cord mod in the 103 really gave a lot of bass power and detail.

I see that your output module is discrete so it will benefit from a good reg... consider building some LM317 / 337 setup... this will boost even more the overall performance.

Ricardo

Thanks for all the suggestions,

I am making some leads this afternoon hopefully so with any luck I should get to see what it sounds like stock over the weekend and then make some decisions about upgrading or not

at present all looks ok with no bulging or leaking caps so I am tempted to run for a while to make sure all is ok

Ian

It will be alright. Mine worked flawlessly for more than 30 years in stock form. Now it has a new life.

Took me 3 hours last night to solder 1 din plug lead. It didn't help with the cable being too big for the plug body but I think I have the technique sorted and only 3 more cable to go now!

Its finally up and running and sounding very very good - I am well impressed.

If it sounds that good in stock form, imagine what it can do with a little work.

Ricardo

I've been doing some more listening and think I am remembering why I have used valves for longer than I remember. For music I find its a bit sterile and non involving compared with my previous concordant/leak set up. Having said that its better for AV.

Longer term I still hanker after trying a Chord.

I think I will try and source another set of power amps either 103D or pair of 105s and try bi amping see where that gets me.

Then consider the upgrade route

Just taken the Rothwell attenuators out of circuit and changed to the tape input and things are starting to sound more dynamic. Am watching some 105s on ebay but at over £300 and 4 days still to go they are looking a bit pricey for me

The trick is to upgrade the 103 psu caps... do the power cord mod (unbeliveable bass detail) and recaps the 101 with 680uF BG Nx after the regs.

You will be amazed.

Ricardo

Just got my hands on a pair of 105s and I am, to say the least, puzzled. The guy who sold me them gave me din to din leads to connect them up and told me that you daisy chain the signal leads - pre amp to the first power amp and then from the first power amp to the second. All of which sounded plausible but getting every thing home the amps have left in and right in dins which suggests I need a split pin.

When I look at the leads he gave me I am starting to think they are from something completely different. Pin 1 goes to 4, Pin 4 goes and 1 and 2 goes to 2 but on both leads pins 2 dont seem to pass a signal almost if they have oxidised up but seems strange that all 4 are the same. They are wired inside ok.

How do these amps wired to to the pre amp signal wise ?

Just put a meter across the power amp input terminals and it looks as if they are wired to allow daisy chaining - should make life easier - guess I just need to wire up to cables 1-3, 4-5 and 2-2 direction code them and I should be in business so to speak - need to check nothing else looks wrong before I hook up test speakers.

the first Power amp module looks sound as does its PSU

Pre amp is fully discrete with a none specified MC module. It has a yellow dot on of that gives any guide

Things get more and more interesting ( probable means expensive) by the minute. Got the 105s wired in and sounding good but it seems to have highlighted a problem with the 103 power amp unit.

One channel is very distorted when fed the high frequency signals.

I have swapped everything round am pretty sure the amp unit is the problem.

Everything sounds fine full range on the 103, everything sounds fine on my test speakers but as soon as I bi amp with the 103 on the treble huge distortion to the high frequencies on one channel. If I swap the 105s and 103 round so the 103 powers the bass and the 105 the treble all sounds ok again.

Any ideas on what might be wrong and any suggestions on who could service. Cant trace Gordon Welford, so Meridian or is there any other meridian series 1 grurus out there?

Actually it is sounding rather good bi amped with the 105s on the treble but i dont want to run for long as there is clearly a problem.

Also the 103 case gets warm but the 105s stay cold

Hi Mr Ian
Judging for you comments you are really liking the Meridians Very good !!!

Did you try the 103 as a full bandwith amp ? (I mean, did you use it alone ?)

Do you use a crossover BEFORE the amps to do the biamplification ?

Do you know the impedance of youe speakers high freq input ?

Ricardo

Hi Ricardo

Yes I have been running the 103D full range for a while and some times it did seem sound a but harsh which may suggest the distortion is there but more hidden full range. I usually use tube amps and having been using an old meridian MCD recently so didn't pay much attention.

It is however very very noticeable on the LH channel when I bi amp.

I am using the speakers internal crossover so the amps are before the cross over rather than a true active set up.

Swapping PSU makes no difference but feeding the LH channel into the RH speaker moves the problem to the opposite speaker. I have swapped the leads rounds and re made speaker connections etc everything points to the Power amp. The LH channel looks as if it has had work done on it before

I think all the drivers have an 8n ohm nominal impedance

Drivers: 8.5" Seas bass; 4.5" Seas mid; Focal TD90K tweeter.
Crossover ponts: 800Hz; 4Khz; 2nd order summed response.

I was using the 105 on the 8.5" base with the 103 powering the other 2 drivers

If I take it locally to a none meridian specialist what are your upgrade recommendations

PSU Caps
The blackgates 680uF Nx - are these replacing the 2 vertical radial caps?
any thing else that makes a dramatic difference without radically changing the amps

Many thanks for your help and advice

Ian

In my case, the two 680uF Nx are on the pre amp 101b, just after the +-15v regulators. (Vertical caps)

I also replaced the regulators by some 317 based ones, and replaced the smothing caps (horizontal 1000uF) by two 3300uF Pana FC.

Finally I replaced the stock rectifier bridge by one based on hexfreds.

But it seems your problem is inside the poweramp.

Open it and see is it has been modified. The electrolityc caps (100u) my be faulty so I would recommend to replace them.

http://www.diyaudio.com/forums/showthread.php?postid=1657604#post1657604 As you can see, my 101b is different from yours, so I had space for the 680u Nx

Hi Ricardo

If i need to get some one to look at the Power amp - might as well get the pre modded at the same time if the caps will fit.

The Power amp looks as if it has had some repairs. The outputs differ. Some resistors are different and some of the some silver canister type components are different. Not sure what these are unless they are just covers/shields that are missing.

I have marked examples here

http://i665.photobucket.com/albums/vv15/Mr_Ian/103internalrepairs.jpg

The caps look original

Bearing in mind the 103 gets very warm to touch and the 105 stays quite cold could the fault be a bias issue?

Hi Mr Ian

Looks like the 103 has had major surgery. It should not get hot... It only heats up when driving low ohm speakers at full volume.

Try mailling Colin (thecolinhoward@blueyonder.co.uk) he used to work on these.

Please report the evolutions .

Ricardo

Hi Ricardo

Going to mod the 101 - where did you get the Blackgates? understand they are in short supply these days. Think I can get them from US but if you know a reliably supplier that would be good

Many thanks

Ian

Partsconnexion has stock of some blackgate sizes, the rubycon a series caps are very similar.

Hi Ian

Partsconnection has got the BG. the issue might be the importing tax costs. You can also try THL Audio from hongkong.

Please beware of the cap sizes.... Only BG Nx 680uF 35v has the correct height (24mm).

BG where made by Rubycon but there is no cap like the Nx series for this purpose.

You will love this mod. (Loads of detail and very powerfull bass)

Ricardo

many thanks for all your help - let you know how I get on

"This brings back so many good memories, especially of the original three-module 101 with 103d amp. Worked so well with Harbeth HL's and Tangent RS4's IIRC. "

I just bought a 103D and have both 101 and 101B. I'm looking for a pair of compact speaker that would go nicely with this kit. Are you talking about the Harbeth HL-P3ES2?
Any other suggestion for speakers? Many thanks.

Anybody know how to convert the 103.5 power supply of a 103D from 220V to 110V? Thanks.

Anybody know how to convert the 103.5 power supply of a 103D from 220V to 110V? Thanks.

PM me (include your email address) and I can send you instructions - or contact Dave Hall at Meridian - he's usually only too happy to help.

After succesfully recaping the 101b and the 103 PSU, I need to have a go at the power amp.

The first mod I intend to do is basically upgrade the connections between preamp and amp.

In order to build a suitable cable, I need to know the pin connections (DIN plug) inside the power amp.... Can anyone help ?

Best regards

Ricardo

Ricardo - PM me your email address - I have loads of diagrams that may help.

Neil

...build a suitable cable, I need to know the pin connections (DIN plug) inside the power amp....

From the owners manual:

"The input signal to the power amplifier is via the five pin DIN socket pins 3 and 5 left and right respectively pin 2 ground"

Just replaced the stock cable between 101 and 103 with a prototype made of silver 5 pin din plugs, using mogami wire.

Notorious gains in detail but the TT now sounds a little forward. (Must wait to be able to report correctly.... shhhh the solderings are healing nicely).

Thank you Neil for your support :)

Now I am considering replacing the 103 power amp´s 100uF EL caps by some 220uF 35V Ruby ZA.... Should I do it or the 100uF is a critical value ?

Regards

Ricardo