Here is my prototype for a balanced audio preamp, one channel shown here, the reason for me to build this way is that the chassis used is only 35mm high and not much space so the module is only 30x65x80mm
I use a E88CC at 60V with 2SK170 for CCS
Supply is 12VAC pumped up to 60V and regulated with SS9012/SS9013.
I use a E88CC at 60V with 2SK170 for CCS
Supply is 12VAC pumped up to 60V and regulated with SS9012/SS9013.
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.
Hey! that´s a nice amp yové built there. Cool using obscure vt-127A tubes too. What are you using for signal/driver tubes? Care to share the schematic, Ivé got itchy fingers and Im looking for a new projecy, this would suit me just fine
Congrats
Looks nice.
However I'd suggest you crank up the bias and get those anodes glowing. The gettering in these tubes is the gray Zirkonium 'powder coat' on the anodes, and they need to be red hot for it to work. You risk that the tubes might not last long if you run them cool. Quite the opposite of ordinary audio tubes.
Cherry red to a dark orange will do. No need to worry, they can take it.
- Frank.
Looks nice.
However I'd suggest you crank up the bias and get those anodes glowing. The gettering in these tubes is the gray Zirkonium 'powder coat' on the anodes, and they need to be red hot for it to work. You risk that the tubes might not last long if you run them cool. Quite the opposite of ordinary audio tubes.
Cherry red to a dark orange will do. No need to worry, they can take it.
When I was a kid my mom used to fire up a kerosine lamp during power outages. It was nice and warm..
When I was a kid my mom used to fire up a kerosine lamp during power outages. It was nice and warm..
When I was a teenager my mentors used to fire harsh words at me for ignoring Eimac's recommended operating practices for power tubes...
Thanks for the schematic mindutis. Do i need any feedback in pentode connection?
@felixx: Right now i'm using some old tesla speakers with small diy horns. Just testing diffrent constructions. I will eventually build a fullrange system. I need something efficient and small. And not to expensive..
Mullard 3-3 Stereo.. does that make it a 5-3+3 ??
I recently completed this little amp using the mullard 3-3 design, all the valves and transformers are ex equipment but most of the small components are new. I am realy impressed with the sound and for a low powered amp it goes quite loud. This was my first attempt at building a valve amp and next time I would like to build a SE design with a little more power !
I recently completed this little amp using the mullard 3-3 design, all the valves and transformers are ex equipment but most of the small components are new. I am realy impressed with the sound and for a low powered amp it goes quite loud. This was my first attempt at building a valve amp and next time I would like to build a SE design with a little more power !
Attachments
Yesterday I finished Red Light District amp based on Russian pentodes 6p14. Polish custom OPT by 4pietro. Chassis - recycled from 3Com ethernet hub - did not have to drill LED holes.
Now sitting and sipping Quinta da Espiga, listening to divine Mariza. No v-liquid, SY!
Many thanks to SY and Toni for helping on negative feedback wiring issue.
Now an eclosure to be made.
Inside
Now sitting and sipping Quinta da Espiga, listening to divine Mariza. No v-liquid, SY!
Many thanks to SY and Toni for helping on negative feedback wiring issue.
Now an eclosure to be made.
Inside
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Yesterday I finished Red Light District amp based on Russian pentodes 6p14. Polish custom OPT by 4pietro. Chassis - recycled from 3Com ethernet hub - did not have to drill LED holes.
Now sitting and sipping Quinta da Espiga, listening to divine Mariza. No v-liquid, SY!
Many thanks to SY and Toni for helping on negative feedback wiring issue.
Now an eclosure to be made.
Nice! What kind of enclosure do you have in mind?
Regards
M. Gregg
