Sorry I meant you need 0-200V and 0-6V or something like that, you're fine
Like this but mine is to accommodate 200V caps
@passive420 thanks for clearing that up for me. I'll take the rest of the day off from the forums etc... brain is too fried 😅
I had asked about the 200V being center tapped, because one half of it would be good for producing 135-140V.
OK, I wondered if they could be connected in parallel to half the voltage but double the current rating?
With a full wave rectifier, that would work. But it seems not to be center tapped.
Can the Michelag's Tube I/V work with slightly lower transformer secondary voltage of 120 V / 100mA in bridge configuration or is it to low voltage ?
By simplest calculation this would give only cca. 160 Vdc after rectification or slightly more since the current load would be about third of what is possible from secondary/rectification ( per cahnnel ).
Asking because i happen to have such transformer, 2x 120-0 V-AC / 100 mA + 12,6-0 V-AC / 2A for heaters ( if the HV is doable the heaters would be dropped to work at 6,3 Volts ).
By simplest calculation this would give only cca. 160 Vdc after rectification or slightly more since the current load would be about third of what is possible from secondary/rectification ( per cahnnel ).
Asking because i happen to have such transformer, 2x 120-0 V-AC / 100 mA + 12,6-0 V-AC / 2A for heaters ( if the HV is doable the heaters would be dropped to work at 6,3 Volts ).
Usually calculate this as 120 x 1.35 = 162 so my calculation is on the lower side. Guess there would be cca. 165 Vdc.
Thanks !
I would stay with 100V on the plate unless @Michelag thinks it's ok to move it higher. With the same plate voltage/current and higher voltage additional power will dissipate on Q1/Q2. Maybe increase R2, R3 in the power source? The peak voltage on the caps will go way up so you would need to use appropriate caps.
@passive420, I understand that 180V B+ is with the load. My transformer has 170VAC and under load I have 190V B+. Do you see 180V B+ under the load with 130V AC?
If it matters at all in the discussion...I was planning on using a 6H1N NOS tube.
I've been told it should work fine in this circuit.
I've been told it should work fine in this circuit.
Hg
I bought a whole box from Russia many years ago. It arrived with the military markings and everything on the box. I've never had a package take that long to get through customs before or after that one 🤣
I traded the tubes, except a few, to a guy that built me a tube amp. There was 100 tubes in the box. This was before they realized the real worth of the tubes, I think I paid $60 or something for the entire box with shipping. I have only the one tube left from those now.
It's the -EB version.
I bought a whole box from Russia many years ago. It arrived with the military markings and everything on the box. I've never had a package take that long to get through customs before or after that one 🤣
I traded the tubes, except a few, to a guy that built me a tube amp. There was 100 tubes in the box. This was before they realized the real worth of the tubes, I think I paid $60 or something for the entire box with shipping. I have only the one tube left from those now.
Can go down til ca. 90V, provided there is ca. 60/70V in excess for the CCS
Thanks !
Minimum than but easier to try since i have a transformer, the other one is 240 V-AC on secondary, too much for this, maybe for some other tubes.
Found a couple of hours (the real treasure nowadays is finding time for myself), experimenting with ad1865 (thanks passive!) with opa 1655 at the output.
Boys, this is good.
Almost comparable with 1862+ tube stage, though some bass is missing.
Miro's mini boards and tps7a regs are invisible to the ears.
And yes, the blue boards on the right are Miro's glorious tpa6120 headphone stages 😁
Need something for workplace 😁😉
I've some other opamps to test, some modern ones (and of course Vince/grunf ad811), not the usual ad797... Will write you the names...
Boys, this is good.
Almost comparable with 1862+ tube stage, though some bass is missing.
Miro's mini boards and tps7a regs are invisible to the ears.
And yes, the blue boards on the right are Miro's glorious tpa6120 headphone stages 😁
Need something for workplace 😁😉
I've some other opamps to test, some modern ones (and of course Vince/grunf ad811), not the usual ad797... Will write you the names...
Attachments
Such a sad reality when this hobby is making us feel like boys 😁 Found myself not having 30mins for this, let alone listen to music with pure intent to listen to it, very unfortunatelly.
Even though opa1655 (opa1656) is my favourite chip opamp, i would suggest you to try opa1641 with ad1865. That should bridge that gap you mention 😉 For some reason, they trully are a great match, has more bass in comparison to opa1655, and it mellows it more into what is usually called analog like.
Found a couple of hours (the real treasure nowadays is finding time for myself) :
+1 ; I looked for some below the carpet, and I did find any, alas ! Just some dust I forgot to vacum last time !
I see you had a spaghettis temptation ! 😛
+1 ; I looked for some below the carpet, and I did find any, alas ! Just some dust I forgot to vacum last time !
I see you had a spaghettis temptation ! 😛
Already on my list:
Opa1611
Opa1642
Opa1655/56
Opa627
Ad797
Lme 49710
Lme 49990
Lt1028
And of course Miro's tpa6120, and as said, ad811