Another Carver 4000t Pre in work

WOPL Sniffer

WOPL Sniffer

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Screw it
Just got my Carver 4000t from Fedex and I stripped it down to bare chassis. I'll start recapping the boards, and I'm glad I got reminded that I needed some RC4136N's.... I'm down to just a couple left. I should probably send Mouser a note telling them that they got these listed as SMD/SMT....... Any-who, it's in nice shape and has a build date of 1986 so this should be a late build. A couple knobs have chipped paint but I think I have a green set ready to go :)

This will go in my rack with the Jolly Green Giant, and my Sansewer TU-517 (LED's should be here in a day or two)...... Oh, and my Turn Table which changes color with the touch of a button.......
 
Well, I couldn't just order opamps.... I blew another $75 on some caps. I go through tons of 1uf, 2.2uf, 3.3uf, 4.7uf, and 10uf electrolytics...... I have most other sizes on hand.
 
My wife always hates Mouser order day. I say I need $50 to $75 worth and it always doubles.
 
I just finished the game board. And the power supply module. I'm just poking along
 
You had me at the game board, I knew Bob Carver was a visionary but wow installing a channel for gaming now that is forward thinking o_O
 
are those new PCBs for the 4000t or the old ones (because they look new) you are populating?
 
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Yes, I had these made from my schematics. The gain board, makes it easy to change the gain of your preamp as prescribed in the service manual. On my board all you have to do is change the jumper to the corresponding gain setting if you want to adjust it.

in the service bulletins for adjusting the gain, it has you pull the resistors. I removed them and put my game board in and now it's just a jumper setting it takes one minute after removing the bottom
 

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stetter said:
are those new PCBs for the 4000t or the old ones (because they look new) you are populating?
Click to expand...


The Gain Boards will fit most pre's (Carver) if they have a service bulletin for gain adjust (C-1, C-4000, 4000t, etc), and the power supply module can be adapted to many also (Not the C-4000 since they have the power supply blended with the rear amp). The other board I'm putting in, can be used with the preamps that have the holographic circuitry in them (C-1, 4000t, and others). I didn't design the Holographic board, that was done by the guys on The Carver Site. I did use their schematic and built some for my equipment I upgrade, and they don't mind it as long as you don't sell them on ebay. The guys over there actually fixed the shortcomings of the original design and now they work great (I use mine all the time. Me and Glen have been using these 3 boards when upgrading the preamps we get our hands on. The Power supply module I swear by. The power supply circuitry on the pre's from Carver, is pretty much rudimentary and the +12VDC can hover around 9 volts, and the -12vdc can be all over the place. I myself believe that if you have a steady clean 12 volt power supply that the unit will perform better (consistent). When installed, the + and - 12vdc at pretty much spot on (within 50-100mv) and you can play with the caps on the module if you have any noise but it works great. It's easier to deal with issues within a unit, if you know wherever you check, that you have spot on voltages and the units coming off the street, are all over the board. I say if you have a 12 volt power supply, it should put out 12 volts even if some of the opamps and shit can work with 6-18 volts. Plus, I double up on the heat sinks and it runs warm (not hot) and the power is clean on the scope. But hey, that's just my take. I have yet to have a power supply issue since using them. I have passed some of the boards around so if you want to try one, let me know, postage is all I ask (for the bare board) or $15 populated. I remove the original regulators off the power supply and run wires from the module to where the regulators mounted. 6 wires is it...... Plus it has LED's on it so at a glance you can see if your 12 volts it there. I'll drop a pic as soon as I get done stuffing my face.
 
Here is the 4000t power supply with the original regulators removed and the ps module jumpered in. It will get attached to the chassis. I used to screw them to the chassis but just use a couple of pieces of double sided foam and a dollop of rtv on the corners. On the original ps, I put in fresh caps, new 4004 rectifier diodes, cleaned and GREASED the pots after cleaning the dried up stuff out, checked/reflowed solder joints and got rid of the flux mess. It's ready for install.
 

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I will let you know when I tear into the 4000C I picked up. I like the idea of stable power for it but sounds like it might not work for my model. But some of the other board sound like the cats meow. I do like your work, some of the best you get to look at. I will let you know after more research and deconstruction.
 
I used to mount the boards to the chassis but it made for a pain in the ass for disassembly.
 
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