Carver 4000t Preamp rework/rebuild

[WOPL Sniffer]

Carver 4000t preamp

Any tips on rebuilding one of these? I got one coming to the shop in a week or so. I didn't find much on mods or a recap/parts list.

 

[grapplesaw]

I will be interested in what you do to it as I have two. One is 4000 and other 4000t

i want to add a remote volume controler like this on eBay

ALPS motor potentiometer 3way 2.0 input Remote volume control Preamplifier Completed board+LED display 3 way 2.0 audio channel input

2 remote control for the general purpose of a lot of buttons no effect, only (switching INPUT) (mute M) (volume +VOL+) (volume -VOL-) useful LED display volume CPU board size: 102x38MM motherboard: 70x60MM

​

Here is the service manual Perry.

http://thecarversite.com/manuals/mandir/Carver C-4000 service manual.pdf

There is a couple of good threads in the forum here with upgrades for caps and opamps and some trouble shooting.

The 4000t is only diffferent in the amount of time delay of the effect speakers.

Lots st to read about in this operator manual.

http://thecarversite.com/manuals/mandir/Carver C-4000 owner manual.pdf

 

[marcok]

I have a C 4000 preamp and till now I have only deoxed pots and switches ( every ten years )
Chassis and connectors , etc .are the same as PL 4000 series 2 . ( very good )
Recapping probably is useless , but ....
Remember that recapping it's necessary for PL 4000 series 1 ,
because all the 1uf and 2.2 uf have too low working voltage .
I suggest only to replace the rear speaker connectors with banana connectors .
Ciao
Marco

 

[WOPL Sniffer]

Just finished up the Carver 4000t Preamp rework/rebuild.... It sounds very nice. I rebuilt the complete Power supply (+ and - 12 volts were kinda noisy), I did audio grade on all the caps which touched the 12 volts on all boards. The connectors and switches were dirty so I cleaned them, secured the floppy boards, and replaced a few other Electrolytic caps on the other boards (especially the noise reduction board).... I like the results. Should last for many years. He will be running this along with the WOPL Clair I built him.

 

[Bradrock]

Wow, That's a clean looking unit. I was looking at an SAE amp just like yours on Ebay. And an audio analyzer too.
I will be needing a preamp fairly soon.
How does this Carver compare to the PL4000?
Of course I know either are amazing after your magic touch.But just generally speaking, Does one have a better rep than the other?

 

[WOPL Sniffer]

Wow, That's a clean looking unit. I was looking at an SAE amp just like yours on Ebay. And an audio analyzer too.
I will be needing a preamp fairly soon.
How does this Carver compare to the PL4000?
Of course I know either are amazing after your magic touch.

This is the amp I have listed on flee-bay (analyzer too).

I don't care for the 4000 series 1, but the 4000 series II has a big following. Hard to find although there is one Series II on the bay right now. A lot of his stuff (Bob Carver) looks the same as PL stuff pretty much on the inside.

 

[marcok]

I have a Carver C4000 and my father has 2 PL 4000 series 1 .
Carver C4000 looks smoother than PL 4000 that I consider aggressive .
Any way the circuits of both preamps are very standard ( except for special function ) .
PL 4000 is based on BC 237B and C 4000 on RC 4136 ( quad 741 ) .
These two preamps should be used if you appreciate the special functions .
( like me and my father ) .
Ciao
Marco

 

[WOPL Sniffer]

Just got a call from my buddy Chris for whom I built a Fresh WOPL 700 II and did the Carver 4000t rework. He said he wet himself and I asked if he got shocked, he said no, the amp and pre sound so awesome and quiet that he was speechless. Now, maybe he'll quit talking about his Macintush stuff.....

I love it when I hear from a totally satisfied customer. BOINGGGGGG.

 

[WOPL Sniffer]

this is how they leave the factory. That flux causes corrosion and stray capacitance.......... IT'S GOT TO GO.............. The function switch was corroded and loose, tapping it made the system cut in and out. It's all good now, clean clean clean, re flow solder, use the ruby red eraser on the contacts... Very time consuming. I am going to find me a Carver 4000t. When reworked correctly, they pay off in sound 10 fold.

 

[WOPL Sniffer]

I rebuilt 99% of the power supply. It was a bit noisy (not the worst I have seen). New + and - 12 volt regulators, got rid of the cheesy heatsinks too. New diodes for the rectifier, new Caps. I changed out ALL the caps which touched the + and - 12 volts throughout the Preamp.

 

[laatsch55]

LM317 regulators?

 

[WOPL Sniffer]

L7912CV and L7812CV

 

[laatsch55]

Ah......

 

[Bradrock]

What are the differences between the Carver 4000t & the c4000? I've watched several c4000's on the bay , but no 4000t's yet.

Thanks, Brad

 

[WOPL Sniffer]

If memory serves me, the C-4000 is set up for a center, left, and right time delay set of speakers (small screw terminals on the back of the pre), whereas tbe 4000t has a set of terminals on the back for rear surround speakers (just one speaker).

 

[grapplesaw]

The difference is the amount of time delay for the delayed speakers settings. I believe the c4000T has 5 ms less delay than the c4000for each stting

 

[marcok]

Not only !
4000 has no MC input and no digital lens .
4000t has no peak unlimiter and no power amp for rear speakers.
Ciao
Marco

 

[grapplesaw]

The difference is the amount of time delay for the delayed speakers settings. I believe the c4000T has 5 ms less delay than the c4000for each stting

My appoligies on this subject. I had two C4000, on gold trim and one gun metal. They had two different time delay times. I switched the gold face plate and knobs onto the gun metal one which had the shorter delay time and then sold the longer delay time unit, now gun metal one. I had in my mind it was a c4000t but now see there were two different offerings of the c4000. So the C4000t is quite different. I will stick to the c4000 over the c4000t. I currently have two gold face c4000 units. I plan to redo one this winter as per upgrades listed in this forum

 

[grapplesaw]

The difference is the amount of time delay for the delayed speakers settings. I believe the c4000T has 5 ms less delay than the c4000for each stting

My appoligies on this subject. I had two C4000, on gold trim and one gun metal. They had two different time delay times. I switched the gold face plate and knobs onto the gun metal one which had the shorter delay time and then sold the longer delay time unit, now gun metal one. I had in my mind it was a c4000t but now see there were two different offerings of the c4000. So the C4000t is quite different. I will stick to the c4000 over the c4000t. I currently have two gold face c4000 units. I plan to redo one this winter as per upgrades listed in this forum

 

[marcok]

I have checked the C 4000 versions
Before 1982 time delay is 35/50 ms and after is 16 /25 ms .
Furthermore there is a version with MC input .
My version is the first one .

Ciao
Marco