Meridian 101 Pre-amp Questions
- Thread starter Mus
- Start date
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
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 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 ?
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
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
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
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
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.
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?
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 ([email protected]) he used to work on these.
Please report the evolutions .
Ricardo
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 ([email protected]) he used to work on these.
Please report the evolutions .
Ricardo
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
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
"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.
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.