Micro Amp Fever: What Have You Done?

wangdaning

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How do the channels differ? I see different numbers of knobs on each side, but the Bassman (at least the 5F6-A) has mostly 'symmetrical' channels.

I'll be interested in the build thread revival!
Channel one got the bright switch and channel two a deep switch, otherwise the same. The extra two knobs at the end are presence and MV. I will probably remove both once I get the cabinet and do the faceplate, as the presence does not do much and the MV is kind of unnecessary for me. Voltages are not correct there, but that is the idea.
Bassman Micro EF80 Schematic v6 Final Without Voltage.png
 

cometazzi

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Channel one got the bright switch and channel two a deep switch, otherwise the same. The extra two knobs at the end are presence and MV. I will probably remove both once I get the cabinet and do the faceplate, as the presence does not do much and the MV is kind of unnecessary for me. Voltages are not correct there, but that is the idea. View attachment 976426

Ah, very nice! Yes, it was the mismatched knobs that made me wonder.

What is the program you used for the schematic?
 

cometazzi

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bmoney

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Over the past 2 years I've built versions of Rob Robinette's micro amps. First the Deluxe Micro, then the BlackVibe Micro, a Bassman Micro, and most recently a 6G3 Micro (based off of plans someone put up on this forum). They've been great. My wiring looks really ugly, but all the amps work just fine. I've learned so much and got lots of help from people in this forum. The amps all have their own personality and tone and are exactly what I've been looking for. I might make a Champ micro with a switchable blackface tone stack some day. Hard to stop once you've got all the tools.
IMG_5451.jpg

IMG_5452.jpg

IMG_5453.jpg
 

owlexifry

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i’m looking at doing this one someday in the future.
got some EF80 tubes on the way.

my immediate concerns are:
- how to get the preamp plate voltages high enough, when the EF80 power tubes can’t take more than 300V…

options:
1)
- x2 separate HT windings, into separate x2 SS rectifiers. B+ from x1 goes to (2x)EF80 plate + screens. the other (higher B+) goes to PI+preamp
2)
- i don’t even know if it’s possible, and it’s probably a terrible idea: but is it possible to: route B+ first to PI, then preamp, and then final B+ for the EF80 plate+screens at the end..
(unusual scenario where power tubes require lowest plate voltage)
another idea for this:

split / parallel B+ supplies?
1650935538681.png


please feel free to comment on how terrible this idea might be..
 

RicciAntoni_07

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You all are so lucky!! I am praying my first build the EF80 from Rob, will work. All these builds look amazing! Good work folks.
 

vvelt

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It's a self split push-pull. I sourced parts for this based on Gary Gerhart's circuit; here's a pretty good write-up on the amp:


Here's the parts list I used:

Gilmore-Jr-Parts-List.jpg


Gilmore-Junior-Board-Layout.jpg
It's a self split push-pull. I sourced parts for this based on Gary Gerhart's circuit; here's a pretty good write-up on the amp:


Here's the parts list I used:

Gilmore-Jr-Parts-List.jpg


Gilmore-Junior-Board-Layout.jpg
What transformers did you use for this? Did you have the custom MM’s?
 




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