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Thoughts on the 835 Bassamp?
#7
(11-26-2017, 12:07 PM)Hangman Wrote: What is the date code for your 835?

The serial number, as seen from thee tube chart linked above, is 203160. As I understand it, the first three digits put it in the 3rd month of 1962.


So, the maintenance slog through the amp is officially underway. The "before" photo of the guts of the power section is here. From my perspective, the first thing that has to go are those blue Atoms. While there is nothing really wrong with the way the main power supply filters for the power tubes were installed, the three atoms on the preamp section are simply connected to the existing can, effectively doubling the capacitance. That would be, that is, if that multicap was in any condition to function. Not best practice.

The problem is that the first can is a 30/20/20/20 at 500 volts. Those seem to be unobtainable. I suppose I could custom order one, but I opted for the more cost effective approach of restuffing the existing can. I've never done this before, so it was a bit of a ride. But here are pics of it before, opened, restuffed, and finished.

If you are interested in doing this yourself, I used Nichicon caps, mouser part numbers 647-UCY2H220MHD (22uf) and 647-UCY2H330MHD (33uf). These are great caps! 500 volts, 105C, 10,000 hours life expectancy. All four caps for less that $10. It did take an entire evening, however, mostly due to the fact that I had to solve the problem of getting the guts of the can out of the base. Heat gun was the solution. Smelled really bad, though. Note to self: install some kind of ventilation in my shop.
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Messages In This Thread
Thoughts on the 835 Bassamp? - by jjmt - 11-18-2017, 06:28 PM
RE: Thoughts on the 835 Bassamp? - by jjmt - 11-20-2017, 08:19 AM
RE: Thoughts on the 835 Bassamp? - by jjmt - 11-21-2017, 08:20 AM
RE: Thoughts on the 835 Bassamp? - by Hangman - 11-26-2017, 12:07 PM
RE: Thoughts on the 835 Bassamp? - by jjmt - 11-29-2017, 10:26 AM
RE: Thoughts on the 835 Bassamp? - by jjmt - 12-03-2017, 06:04 PM
RE: Thoughts on the 835 Bassamp? - by jjmt - 12-12-2017, 07:17 AM
RE: Thoughts on the 835 Bassamp? - by Hangman - 12-15-2017, 09:28 PM
RE: Thoughts on the 835 Bassamp? - by jjmt - 12-17-2017, 08:27 PM
RE: Thoughts on the 835 Bassamp? - by jjmt - 12-19-2017, 09:04 PM
RE: Thoughts on the 835 Bassamp? - by jjmt - 12-23-2017, 10:51 AM
RE: Thoughts on the 835 Bassamp? - by jjmt - 12-26-2017, 06:55 AM
RE: Thoughts on the 835 Bassamp? - by jjmt - 01-05-2018, 07:52 AM
RE: Thoughts on the 835 Bassamp? - by jjmt - 02-05-2018, 08:49 AM

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