Thanks guys.
It sounds great to me 6L6, very sensitive input though.
stajo, the 6JN8 is basically a 6GH8 with different pinout. Based on the triode-strapped pentode curves I found online for the 6GH8. They were fairly accurate. At the bias point I'm using the mu is about 20.
Not sure about a circuit board yet. We'll see how this turns out.
I was way off on the input voltage readings. Still about 9W RMS though. I'm not sure what happened, I must have been looking on the wrong scale or something on my scope. I took the measurements again.
I will open another thread in the tubes/valves since I don't want to violate the photo gallery rules and talk too much about this.
It sounds great to me 6L6, very sensitive input though.
stajo, the 6JN8 is basically a 6GH8 with different pinout. Based on the triode-strapped pentode curves I found online for the 6GH8. They were fairly accurate. At the bias point I'm using the mu is about 20.
Not sure about a circuit board yet. We'll see how this turns out.
I was way off on the input voltage readings. Still about 9W RMS though. I'm not sure what happened, I must have been looking on the wrong scale or something on my scope. I took the measurements again.
I will open another thread in the tubes/valves since I don't want to violate the photo gallery rules and talk too much about this.
Aikido (circuit in revision! this is old pictures)
Hard wiring:
top:
Kt88 or 120 PP amplifiers:
Hard wiring:
top:
Kt88 or 120 PP amplifiers:
If you need a trafo, here is one.
🙂cop: Link removed by moderators)
I like this people who do with nothing more then we do with much.
sustainability do we call this, but hee it do weld fine.
hee nice 2A3 amp.
regards
🙂cop: Link removed by moderators)
I like this people who do with nothing more then we do with much.
sustainability do we call this, but hee it do weld fine.
hee nice 2A3 amp.
regards
this an 832 pp amp in the works, OPT is 8k a-a to 8 ohms,
concertina drive, 12at7, a line amp using the 12au7 is built in,
and a vsps phono stage, makes this amp a full function integrated amp...
and no GNFB with the addition of the line stage...
this is my parallel SET using the 4P1L's, OPT is 2.5k to 8 ohms,
target operating point is 250 volts at 60mA..
input voltage amp is a 6J9 in pentode mode for more gain,
a 6N1p in a broskie cathode follower config to drive the output stage grids...
another 6550 pp amp good for about 50 watts per channel..
OPT is a 431 like without the ultralinear taps, since i am operating the 6550's in pentode mode....
12BY7 input and 6CG7 LTP phase splitters complete the tube line-up...
concertina drive, 12at7, a line amp using the 12au7 is built in,
and a vsps phono stage, makes this amp a full function integrated amp...
and no GNFB with the addition of the line stage...
this is my parallel SET using the 4P1L's, OPT is 2.5k to 8 ohms,
target operating point is 250 volts at 60mA..
input voltage amp is a 6J9 in pentode mode for more gain,
a 6N1p in a broskie cathode follower config to drive the output stage grids...
another 6550 pp amp good for about 50 watts per channel..
OPT is a 431 like without the ultralinear taps, since i am operating the 6550's in pentode mode....
12BY7 input and 6CG7 LTP phase splitters complete the tube line-up...
6н1п + 6п14п.SE без оос
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Nice!
Clever way of making the big power transformer proportionally to the rest of the components..
Clever way of making the big power transformer proportionally to the rest of the components..
SE 813 guitar amp
OK, not an audio amp but it has been so long since I build my guitar amps that I just had to do it 🙄
And besides, it is a test setup as well for the 813. Another step towards getting them into my audio system.
It uses the external power supply that I can use for either my 300B mono's or the upcoming 813 mono's.
Right now they run on a measly 350V, producing around 5W (10% of the filament power
).
The filament runs on dc using Tomchr's universal filament reg. That 5 Amps is the limit of the LM22679 IC but it works well. Slow start and dead quiet.
Driver is an EF184 with a 2V red LED and a 10M45S CCS.
Next step: upping the HT 3x...
OK, not an audio amp but it has been so long since I build my guitar amps that I just had to do it 🙄
And besides, it is a test setup as well for the 813. Another step towards getting them into my audio system.
It uses the external power supply that I can use for either my 300B mono's or the upcoming 813 mono's.
Right now they run on a measly 350V, producing around 5W (10% of the filament power
).The filament runs on dc using Tomchr's universal filament reg. That 5 Amps is the limit of the LM22679 IC but it works well. Slow start and dead quiet.
Driver is an EF184 with a 2V red LED and a 10M45S CCS.
Next step: upping the HT 3x...
Attachments
Hi Esteban,
This one is regular SE, 6k2 > 8 ohms.
A single tranny that I had on the shelf.
The stereo will be parafeed. Still saving for the PF iron, the other parts I already have: Johnson sockets, PF caps and Mullard power valves 😎
This one is regular SE, 6k2 > 8 ohms.
A single tranny that I had on the shelf.
The stereo will be parafeed. Still saving for the PF iron, the other parts I already have: Johnson sockets, PF caps and Mullard power valves 😎
Ah so we can post instrument amps? Here is my bass guitar amplifier:
It's basically built on top of an op-amp based parametric tone control, tight fit indeed. Power amplifier is a pushpull 6FD7. HT+ is using an SMPS that was meant for Nixie tubes to save space and cost. OPT is a power transformer with 220-110-0 primary and 0-4.5V secondary as output to speakers. Puts out around 7-8 watts. It still needs more gain so there will be a 6N23P/6N2P gain stage at the input. Quite surprised with the wide frequency range the OPT transformer is giving!
It's basically built on top of an op-amp based parametric tone control, tight fit indeed. Power amplifier is a pushpull 6FD7. HT+ is using an SMPS that was meant for Nixie tubes to save space and cost. OPT is a power transformer with 220-110-0 primary and 0-4.5V secondary as output to speakers. Puts out around 7-8 watts. It still needs more gain so there will be a 6N23P/6N2P gain stage at the input. Quite surprised with the wide frequency range the OPT transformer is giving!
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