Please continue to satisfy my tube porn........
Sorry I mean valve and tube last!!!!
thanks i have over 3000 tubes in my stash, mostly TV tubes, i also conduct teach ins and build outs in Manila..
My building partner is enamoured of this chassis construction: https://www.itishifi.com/hifi/electra-fidelity-845-ham-chassis-style
and higher-res pictures will be up for a while at https://www.ebay.com/itm/3257529812...KUfUWgvELDscGg4+K/ph+eoy/U|tkp:Bk9SR5r3sOiBYw
It looks like a rack panel with conventional Bud/Hammond chassis' grafted on front and back. Very clever and pretty, by Jack E of ElectraPrint fame.
We'll probably do the amps (must be bi-amp'd, they have DSP crossovers with delay) for his coming Jubilees this way, and one of us will post pix.
All good fortune,
Chris
and higher-res pictures will be up for a while at https://www.ebay.com/itm/3257529812...KUfUWgvELDscGg4+K/ph+eoy/U|tkp:Bk9SR5r3sOiBYw
It looks like a rack panel with conventional Bud/Hammond chassis' grafted on front and back. Very clever and pretty, by Jack E of ElectraPrint fame.
We'll probably do the amps (must be bi-amp'd, they have DSP crossovers with delay) for his coming Jubilees this way, and one of us will post pix.
All good fortune,
Chris
I did not forget but life got in the way, also had some issues with the amp which are now fixed (thanks to the helpful people on this forum).
My subjective thoughts on the sound: Really good bass, dynamic and full-bodied while not being boomy in any way. I feel like my speakers which aren't tuned all that low gained some low-end with this amp in comparison to my other tube amps (EL34/EL84). Voices sound natural and highs are crystal clear but the difference to my other amps is not as big as in the low end, dynamics are improved across the band.
Now the GM70s "only" run at ~850V and i've read a lot of posts saying that they won't sound that great below 1kv but all i can say is that this is the best sounding amp i own right now.
The transformer covers are actually "designer" brass Plant Pots
Oh yea, i underestimated the amount of heat this thing gives off with 160W of dissipation per tube, really only an amp for the winter time
Attachments
Thanks!
Final schematic for now is this:
However i'm planning on building an A2 driver stage in the future as per euro21's suggestion here.
Final schematic for now is this:
However i'm planning on building an A2 driver stage in the future as per euro21's suggestion here.
Nice work, you've done a cracking job there, could we have some pics of the underside of the amp please? Layout wiring etc. What OPT's did you use? EI or toroid? A mate of mine is planning to build a similar amp. Lastly have you done any bench testing - max OP power,frequency response & THD etc?
Andy.
Andy.
Appreciate it!
There is a pic of the underside here and some measurements can be found in my thread about the oscillation issue i had with this amp here.
OT's are Toroidy TTG-GM70SE.
I only measured power output, have no means to measure thd or response atm. I can get 13W into 8R at the onset of clipping (both channels loaded).
There is a pic of the underside here and some measurements can be found in my thread about the oscillation issue i had with this amp here.
OT's are Toroidy TTG-GM70SE.
I only measured power output, have no means to measure thd or response atm. I can get 13W into 8R at the onset of clipping (both channels loaded).
Thanks for those links, I think my mate is using the toroidy OPT's too. 13w total OP into 8r is a bit bit mad though when you think about it, with a HT of 850v & filaments at 30w approx. I know, SE Class A but I do wonder about our sanity sometimes, the length's we go to to build amps. Still, all the best people are a bit touched.
Andy.
Andy.
It's all the tube can do at that voltage in A1 operation, that's why i wanna go A2 in the future to hopefully get close to 30W out.
Filaments are 60W a piece by the way, not 30
Yes it's a bit mad and not an amp to run all day for background music. this is something for when i get home from a long day at work, crack open a cold one and put on a good couple of records to just enjoy the music, nothing else.
Filaments are 60W a piece by the way, not 30
Yes it's a bit mad and not an amp to run all day for background music. this is something for when i get home from a long day at work, crack open a cold one and put on a good couple of records to just enjoy the music, nothing else.
This is a beautiful build. I also want to imitate nagra like this. I’m currently under moderation on this forum but could you message me so I can ask you a few questions about the parts for this build?
The transformer covers are actually "designer" brass Plant Pots
Beautiful work! And excellent idea with the pots. Amazing how DIYers find inspiration anywhere we go.
Here's an amp I finished recently, a tube headphone amp. I've planned this one over the past two years. I really love high end headphones, so this is meant to be the very last headphone amp for me. It uses a Dave Slagle AVC in a separate enclosure, cathode biased D3a input stage (can I also use E810F and 6E6P, likely others that are pin compatible), Dave Slagle 1:1 IST, triode-strapped HY69 directly heated pentode output stage wired as a cathode follower with Dave Slagle OPT in the tube's cathode (OPT 6.5K: 300/75/16ohm). The HY69 is biased by the DCR of the output transformer primary winding. Using separate Maida-style regulators for each channel and Rod Coleman filament regulators. Mains transformers are custom from Toroidy.
The amp sounds fantastic, but I still see some behavior on scope that tells me the D3a are trying to oscillate despite using grid stoppers, plate stoppers, and ferrites, so I'm still troubleshooting that.
The amp sounds fantastic, but I still see some behavior on scope that tells me the D3a are trying to oscillate despite using grid stoppers, plate stoppers, and ferrites, so I'm still troubleshooting that.