Thanks ! Well, no : these are industrial terminals which accepts banana plugs and clamping of lugs :
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Thanks, yes ! But sorry : what do you name "plastic base" ? Is it the engraved faceplate ?
An externally hosted image should be here but it was not working when we last tested it.
A+!
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An externally hosted image should be here but it was not working when we last tested it.
se f2a German tubes in power .
amrican tubes in driver .
I thought I had already shared these amps. Maybe it was somewhere else?
A pair of Ultra Linear amps using 12AU7s and 5881's. Iron is from Hammond. Fixed bias and balance adjustable. Both amps exactly same circuit.
The rack mount amp I built for my son's home-recording studio. The other is mine.
Transformers in my amp are under a box built of hardware store aluminum put together with JB Weld. Nameplate is etched brass, paint-filled.
Floyd
Eugene, Oregon
A pair of Ultra Linear amps using 12AU7s and 5881's. Iron is from Hammond. Fixed bias and balance adjustable. Both amps exactly same circuit.
The rack mount amp I built for my son's home-recording studio. The other is mine.
Transformers in my amp are under a box built of hardware store aluminum put together with JB Weld. Nameplate is etched brass, paint-filled.
Floyd
Eugene, Oregon
Attachments
This is my version of a Dyna Stereo 70. The EL34's and transformers are similar, but that's about all. 6SN7 first and second stages, EL34 PP outputs. 0 - 14dB negative feedback only goes back to middle stage diff amp, so better phase margin. Front end is outside of loop. Front end has constant current sink instead of plate R, which drives a follower which has a current source in place of the cathode R. The follower drives the volume control, which then drives the 2nd stage, which is a diff amp, which has a current source in the tail. Switchable Ultra-linear 30W per channel, or Triode-mode 15W per channel. Each EL34 has a bias adjustment pot right next to it, and there's a digital meter that tells you the quiescent current in each tube. The photos are actually obsolete since I got rid of the grid cap front end tube, which picked up a little bit of hum, and replaced it with a 6SN7 - same tube spec wise but no grid cap. Now the hum is reduced to nothing noticeable. The current sink and sources increase linearity, but also power supply hum rejection. I call it, The Musicbox. The keyhole on the front is where you wind it up... (just kidding).
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Spud-Pull
Recently finished this push-pull amplifier. It is basically a Spud in push-pull, hence the Spud-Pull. Two 6E5P per channel, with a phase-inverting input transformer (Reinhofer) and a four-deck stepped attenuator. Both 6E5P share four Cree diodes at the cathode, about 30mA at 200 Volts per 6E5P. Power supply is EZ81 and diodes rectified with pi-filters using R and C. Very simple circuit with a bandwidth of 10 Hz up to 90 Khz (-1dB) with about 3.3 Watts into a 16 ohm load. Only remark is that this amplifier needs full line-out level for max power..
Recently finished this push-pull amplifier. It is basically a Spud in push-pull, hence the Spud-Pull. Two 6E5P per channel, with a phase-inverting input transformer (Reinhofer) and a four-deck stepped attenuator. Both 6E5P share four Cree diodes at the cathode, about 30mA at 200 Volts per 6E5P. Power supply is EZ81 and diodes rectified with pi-filters using R and C. Very simple circuit with a bandwidth of 10 Hz up to 90 Khz (-1dB) with about 3.3 Watts into a 16 ohm load. Only remark is that this amplifier needs full line-out level for max power..
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