Tan Music Man

[pompeiisneaks]

Okay here's my first stab at what I 'think' you meant
Edit: Removing attachment, see below response
~Phil

[Mark]

I may have gotten it wrong Phil, but I thought the 40K was attached to B+1?

[talbany]

Phil
Thanks for the work!
It's close a few things,
The 40k/10w connection should go to B+1 (Plate Supply) Not the screen supply!
The last dropper should be 2k2 not 22k
The 82K bleeder goes between the 40k resistor and B+3 to gnd (see pic below)
The bleeders across the plate caps should be 270K not 150K
Label the rest of the caps 20uf
label the 150k at the end of the string FET resistor
Also the heater windings are on the bottom.The middle winding is for the bias supply.Maybe we can draw that up at some point


Thanks Phil

Tony

[pompeiisneaks]

Try 2, removing the one above as it's wrong:

See my next post later down, that's now 'right' after a few more revisions:

~Phil

[talbany]

Looks good!

Thanks Phil

Tony

[pompeiisneaks]

Fixed, see later post with updated versions. This was also wrong.

~Phil

[Mark]

That's great Phil, and thanks for drawing up the circuit. It sounds like that is Dumble amp that should reside in the Dumble files.

[talbany]

If that's good, then I'll upload the editable sch for everyone and I'll do a layout sometime soon.

DumbleMMPSU.sch

~Phil

Phil
Your welcome to do a complete layout, however it would take me about 10 min to modify my 124 layout in the files section. Your call

Tony

[10thTx]

I took the SCH file that Phil drew up and placed it in the "editable D-files" and referenced this thread (& the other Music Man Dumble thread referenced )

http://ampgarage.com/forum/viewtopic.ph ... 94#p385894

With respect, 10thtx

[martin manning]

Stock MM iron says 5.5K AFAIK..The MM amps had both Hi and low power so I am not sure how they came up with that number..I would try to stay above 4K7.

That must be for 4x 6L6, yes?

I don't know,good question!. I am thinking this is for 34's since I don't know of many 6L6's that can handle that high a plate voltage. Most older MM's came stock with Sylvania or Amperex 6Ca7's I think those were rated 800V on screens
Martin maybe you can run the load lines for us for both tubes.That would be really helpful!!

Yes 6CA7 or EL34 for those voltages (too much for 6L6GC), and 5k5 Zpri looks reasonable from a plate dissipation standpoint.

[pompeiisneaks]

If that's good, then I'll upload the editable sch for everyone and I'll do a layout sometime soon.

DumbleMMPSU.sch

~Phil

Phil
Your welcome to do a complete layout, however it would take me about 10 min to modify my 124 layout in the files section. Your call

Tony

Nah go ahead. I'd say if you can update yours that makes more sense I was just going to do the PS section as an 'addendum' the whole thing with the updated PS would be better.

~Phil

[ToneMerc]

Phil
Thanks for the work!
It's close a few things,
The 40k/10w connection should go to B+1 (Plate Supply) Not the screen supply!
The last dropper should be 2k2 not 22k
The 82K bleeder goes between the 40k resistor and B+3 to gnd (see pic below)
The bleeders across the plate caps should be 270K not 150K
Label the rest of the caps 20uf
label the 150k at the end of the string FET resistor
Also the heater windings are on the bottom.The middle winding is for the bias supply.Maybe we can draw that up at some point


Thanks Phil

Tony

The bleeder to ground should be 820k not 82k.

TM

[ToneMerc]

That must be for 4x 6L6, yes?

I don't know,good question!. I am thinking this is for 34's since I don't know of many 6L6's that can handle that high a plate voltage. Most older MM's came stock with Sylvania or Amperex 6Ca7's I think those were rated 800V on screens
Martin maybe you can run the load lines for us for both tubes.That would be really helpful!!

Yes 6CA7 or EL34 for those voltages (too much for 6L6GC), and 5k5 Zpri looks reasonable from a plate dissipation standpoint.

Martin, I have used 5k to 5.5k.

TM

[martin manning]

There are a few other things about that photo:
The reservoir looks to be 4x 100u, in a 2x2 stack with the screen node taken from the middle. There are no balance resistors; none are needed.
Off the divider there is a stack of two radial caps with 470k balance resistors. I'd guess they are 47u 350V.
Then there are three more 22u caps, but only two dropping resistors. So what's up with that?

[ToneMerc]

There are a few other things about that photo:
The reservoir looks to be 4x 100u, in a 2x2 stack with the screen node taken from the middle. There are no balance resistors; none are needed.
Off the divider there is a stack of two radial caps with 470k balance resistors. I'd guess they are 47u 350V.
Then there are three more 22u caps, but only two dropping resistors. So what's up with that?

Martin, your' right. Node B3 get'sthe totem pole because unloaded with no current draw that node can see over 500v, ask me I know! Then he hangs a 22uf on the screens, B4 and B5.

TM