The project begins ... slowly

[DonMoose]

As I've mentioned, I'm a feature creep, and starting on my nutbar project -
A 'stereo' 50W power amp with one 50W bluesmaster-PI channel and one 50W 'non-BM' channel - thinking half-power 183 here, but open to suggestion.

The power amp input buffers are the Return sections of a DLator.

The (separate) preamps are going to be an assortment of ODS types, and maybe some non-D-style ones; each of these will have a DLator Send section as an output buffer. There will be some sort of switching/mixing/routing thing between the preamps and power amp channels.

Acknowledging that there are more B+ nodes than I really need, that I have to work out the B+ string values and a few other gaps, have I headed in the direction I intend?

Thanks!

[NEjoe]

I'm not sure you need to do dual B+ sections. In addition to taking up less space and costing less in parts, I would think that one power supply rail might be better since both stereo channels will have the same volts, versus a possible variation if you have two.

And the 22uF caps in series will produce an equivalent 11uF cap which might be on the low side.

The last time I priced it out it was less money to buy one high volt cap than putting two in series, but that might have changed.

No reverb? How can you have feature creep with no reverb?

[DonMoose]

The two channels are different PIs, and maybe different tubes - the goal is a BM-style and a 'classic' style power amp to pick from. The independent B+ rails are aimed at allowing me to turn one one, the other or both at will, and to prevent an unloaded power amp from getting power (note B+ switch in speaker jack wiring).

The series-stacked caps are more-or-less the norm around here for the B+ string, but there is some refinement to do.

Reverb is more of a preamp/loop thing, but a bias-wiggler vibrato might find its way in here.

Thanks!

[Structo]

I think what Joe was alluding to was, typically in the precision type power supply the series caps are 47uF, giving a total of 23.5uF in series rather than the 11uF you have there.

As for the switching of B+ on the speaker jacks I don't think that is very safe and may violate electrical codes.

[DonMoose]

I think what Joe was alluding to was, typically in the precision type power supply the series caps are 47uF, giving a total of 23.5uF in series rather than the 11uF you have there.

Even on the 50W models? (familiar with electronics basics - 25+ years as a hardware geek)

As for the switching of B+ on the speaker jacks I don't think that is very safe and may violate electrical codes.

Hmm. Have to think about a relay, then, because I know I'm gonna f' up from time to time.

Thanks!