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- Poland, Warsaw (Central Europe)
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- I love BIG amplifiers!
Carver C-4000 recapping
- Thread starter P.L.F.
- Start date
There's no other path for even greater pleasure of listening to the music, right?
- Joined
- Jan 14, 2011
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- Gillette, Wyo.
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- Halfbiass...Electron Herder and Backass Woof
Today I finished recapping of the other C-4000 preamp I have and this time I did't create any mess 
. For the first time I was using PanaVise PCB holder - what a great tool!!!
The C-4000 sounds so crisp & clear now and with expected bass extension. Surprisingly after recapping the loudness contour function started to work again...?
This unit together with fully comp PL700 II (for cooling there are two 120 VAC fans connected in series); Yamaha CD-S300-RK Rackmount CD Player, where one can plugin an iPod with Apple Lossless files to avoid frequent disk changing, and Yamaha PA S4115H speakers will serve garden parties this summer ...
Pity I live so far from you guys but will try play loud then
...
. For the first time I was using PanaVise PCB holder - what a great tool!!!The C-4000 sounds so crisp & clear now and with expected bass extension. Surprisingly after recapping the loudness contour function started to work again...?
This unit together with fully comp PL700 II (for cooling there are two 120 VAC fans connected in series); Yamaha CD-S300-RK Rackmount CD Player, where one can plugin an iPod with Apple Lossless files to avoid frequent disk changing, and Yamaha PA S4115H speakers will serve garden parties this summer ...
Pity I live so far from you guys but will try play loud then
...
To be honest I have not understood what you mean when you talk about the loudness function related to recapping .
Please explain better .I'm very curious . In my set up I use 40 Hz position .
Ciao
Marco
- Joined
- Sep 9, 2012
- Messages
- 419
- Location
- Poland, Warsaw (Central Europe)
- Tagline
- I love BIG amplifiers!
Thanks Marco!
It is the same function you referred to - see the photo please. I rarely use it however it that second unit I have there was no sound difference at all. After recapping I can hear it working OK when pressed.
Ciao, Przem
P.S. I've attached two brochures on Carver gears...
It is the same function you referred to - see the photo please. I rarely use it however it that second unit I have there was no sound difference at all. After recapping I can hear it working OK when pressed.
Ciao, Przem
P.S. I've attached two brochures on Carver gears...
Attachments
Last edited:
Przem,
I don't know . It's strange for me , but my set up is very complicated .
- tone on ( 2kHz )
-3db trim on
-hologram normal
-hologram angle 125us
-time delay 35ms
-AR 9 flat ( 0 dB ).
It took me about one year to get the best performance in my living room .
At the beginning it was a real mess ,even though Mr. Bob Carver gave me some suggestions .
C 4000 is a wonderful preamp , but it' very difficult to adjust .
When you change one of these parameters the sound changes .
Probably I have masked this effect with my set up , but I'm not sure .
Referring to owner's manual you can see that all the curves ( tones , etc .)
are moreless correlated .
Remember always that the position of speakers is very critical with hologram engaged.
And the last but not the least : the sound is a sensation !!!
Ciao
Marco
I don't know . It's strange for me , but my set up is very complicated .
- tone on ( 2kHz )
-3db trim on
-hologram normal
-hologram angle 125us
-time delay 35ms
-AR 9 flat ( 0 dB ).
It took me about one year to get the best performance in my living room .
At the beginning it was a real mess ,even though Mr. Bob Carver gave me some suggestions .
C 4000 is a wonderful preamp , but it' very difficult to adjust .
When you change one of these parameters the sound changes .
Probably I have masked this effect with my set up , but I'm not sure .
Referring to owner's manual you can see that all the curves ( tones , etc .)
are moreless correlated .
Remember always that the position of speakers is very critical with hologram engaged.
And the last but not the least : the sound is a sensation !!!
Ciao
Marco
Hi,
There were some modernization works of external PS 240VAC line to my house going on when I was listening to the music and apparently something got burned in my C4000. Here is what had happened:
First I heard two/three thumps on the left channel and at the same time a number of clicks of Don's DC protection module, then the channel was dead. I checked fuses on my PL700s2 (the one upgraded by Lee) and one out of four rail fuse went down (5A 240V AGX). After its replacement I put all pots at the minimum and turned on the amp - ufff, it started OK. However the first attempt to increase volume of the amp (I tried about 50% clockwise) started that strange clicking of relays on the DC protection board - so back to zero. While setting the amp volume at about 20% one could hear the music, however only one channels sounded crispy, the other (surprisingly - right) sounded boomy dark... And any movement of C4000 pots or any its button pressed was causing unpleasant harsh sounds on my speakers.
I have another C4000 (candidate for recapping), which was plugged in and everything looked OK. I was trying to roughly verify possible amp's output failure (without opening the gear and measuring for shorted outputs), so I played the music really hard and loud for a longer while. Both channels seem to work in robust way as before (by the way: should I re-check the outputs if there are any shorted transistors anyway?).
Then I took the preamp on my 'bench' and started some basic measurements. One channel output voltage was like 40% of the other with the same level trigged inputs and on the scope it was visible a DC line too. That DC problem with C4000 reminded me something I had read before but could not remember what was it. Finally after reading all the pages of C4000 SM, on its lat page (of course…) there was this kind of issue treated. Bingo! I replaced two FETs (2N5458’s) with BF245C (https://www.fairchildsemi.com/datasheets/BF/BF245C.pdf) and switched on the preamp with no buttons pressed, vol at minimum. I connected signal generator and the scope, increased the volume and the previously unbalanced output voltages L and R were back to order. Then connected music source and headphones. It sounded nice with no any button switched on.
Unfortunately it was only a partial success. When I pushed the TONE button - dead silence… Also the PEAK UNLIMITER seems not working at all…
Well I am lost a bit and need some time to rethink and also - above all - some advice. I suspect PCB connectors, so they will be all re-soldered, but it would be too simple...
Maybe I should also mention that on the tone PCB I have replaced earlier on two IC’s: TL072 with BB OPA2134 and RC4136 with Brown Dog 2xOPA2134 from Cimaron (http://cimarrontechnology.com/rc4136upgradeadapter.aspx). I found this setup sounding just great, incomparably better than the original one. After the failure I tried the original IC’s just in case but it didn’t cure the problem.
The link to C4000 SM is here: https://www.usahifi.com/sites/default/files/product/610/manuals/Carver C-4000 Service Manual.pdf
Any advice what went wrong?
There were some modernization works of external PS 240VAC line to my house going on when I was listening to the music and apparently something got burned in my C4000. Here is what had happened:
First I heard two/three thumps on the left channel and at the same time a number of clicks of Don's DC protection module, then the channel was dead. I checked fuses on my PL700s2 (the one upgraded by Lee) and one out of four rail fuse went down (5A 240V AGX). After its replacement I put all pots at the minimum and turned on the amp - ufff, it started OK. However the first attempt to increase volume of the amp (I tried about 50% clockwise) started that strange clicking of relays on the DC protection board - so back to zero. While setting the amp volume at about 20% one could hear the music, however only one channels sounded crispy, the other (surprisingly - right) sounded boomy dark... And any movement of C4000 pots or any its button pressed was causing unpleasant harsh sounds on my speakers.
I have another C4000 (candidate for recapping), which was plugged in and everything looked OK. I was trying to roughly verify possible amp's output failure (without opening the gear and measuring for shorted outputs), so I played the music really hard and loud for a longer while. Both channels seem to work in robust way as before (by the way: should I re-check the outputs if there are any shorted transistors anyway?).
Then I took the preamp on my 'bench' and started some basic measurements. One channel output voltage was like 40% of the other with the same level trigged inputs and on the scope it was visible a DC line too. That DC problem with C4000 reminded me something I had read before but could not remember what was it. Finally after reading all the pages of C4000 SM, on its lat page (of course…) there was this kind of issue treated. Bingo! I replaced two FETs (2N5458’s) with BF245C (https://www.fairchildsemi.com/datasheets/BF/BF245C.pdf) and switched on the preamp with no buttons pressed, vol at minimum. I connected signal generator and the scope, increased the volume and the previously unbalanced output voltages L and R were back to order. Then connected music source and headphones. It sounded nice with no any button switched on.
Unfortunately it was only a partial success. When I pushed the TONE button - dead silence… Also the PEAK UNLIMITER seems not working at all…
Well I am lost a bit and need some time to rethink and also - above all - some advice
. I suspect PCB connectors, so they will be all re-soldered, but it would be too simple...Maybe I should also mention that on the tone PCB I have replaced earlier on two IC’s: TL072 with BB OPA2134 and RC4136 with Brown Dog 2xOPA2134 from Cimaron (http://cimarrontechnology.com/rc4136upgradeadapter.aspx). I found this setup sounding just great, incomparably better than the original one. After the failure I tried the original IC’s just in case but it didn’t cure the problem.
The link to C4000 SM is here: https://www.usahifi.com/sites/default/files/product/610/manuals/Carver C-4000 Service Manual.pdf
Any advice what went wrong?