3. G2 to G2 winding, G3 to anode.
I did choose plan 3 for my amp: 5Y3 rectified tube, Mullard E180CC driver runs 95V 4.5mA, Svetlana 4P1L (date 6x) runs 235Vak 37.5mA with auto bias. Sound is wonderful. It beats many penthode tube SE amps that I've built before, like 30P1s, El84, 6V6, 6L6GB... even El34, 6550.
I feel new amp has sound quite likes Hytron VT52 amp's sound. One Vote is for them.
PS: I don't know why unable to post pictures and insert emotion icons. Maybe my computer has problem.
I've used exactly that to drive a 300b. I didn't measure anything, however. I swapped fairly quickly to PSE 4P1L because I thought it sounded better.
I've used push-pull 4P1L with interstages to drive PP 2a3 and 6B4G and that worked very nicely.
There is a caveat, you need a preamp with at least 2x gain to get the most of a 2A3/300B driven by a 4P1L. Or a third stage. For the same reason the 4p1L driving the PSE 4p1ls's keeps things 2 stage and could be why it sounds best., but its not going to give 300B power levels.
Personally think a IDHT with gain of 25-30+ giving a 2 stage amplification is more elegant for 2a3/300b tube types.
The "all 4P1L" amp to beat is the P-P as described above, they were designed for this application, but I'm just not into p-p.
Just letting you know that a triode 6e5triode-300B is going to be an much easier possible more elegant build.
If you really are a DHT purist a VT51 is a tube to investigate.
Would a 4P1L with an LL1660/18 4:4,5 (alt S) drive the grid of an 6B4G properly?
Yes, it would be quite perfect. I have that same driving a 300B (that drives a GM70). Go for it
Has anyone set up a 4p1l in an avoIV and know what parameters to use?
Try this (as I did on my Mk.III):
Thumbwheels: 265144300
Filament: 4 volts
Anode: 150 volts
Screen: 150 volts
Neg Grid bias: 8v
I saw 5.5mA/v and 21mA on a sample just now.
There is a caveat, you need a preamp with at least 2x gain to get the most of a 2A3/300B driven by a 4P1L. Or a third stage. For the same reason the 4p1L driving the PSE 4p1ls's keeps things 2 stage and could be why it sounds best., but its not going to give 300B power levels.
Personally think a IDHT with gain of 25-30+ giving a 2 stage amplification is more elegant for 2a3/300b tube types.
Just letting you know that a triode 6e5triode-300B is going to be an much easier possible more elegant build.
If you really are a DHT purist a VT51 is a tube to investigate.
There is the other option of using 4P1L in pentode as a driver , which I have mentioned before, and found to be extremely successful both with 6B4G and 300B .
For an example of the set-up, see circuit attached - just finished building this one for our meeting in Yorkshire last week . This happens to be a two-channel amp to drive two horn drivers , with internal crossovers, but the set-up and principle of the 4P1L driver is there - just build the upper 6B4G channel with a more suitable coupling cap and grid-leak .
This driver retains the 'direct-heated' sound, but achieves more gain without going to three stages or the inevitable low-end time constant of an SE interstage .
Gain on this driver as shown is about 22 , rising to around 32 if you use a cathode by-pass cap .
audio-talk :: View topic - A 2 or 3-channel SE 'Horn-amp'
Last edited:
I'm still using the 4P1L triode strapped to run my horns. Battery bias, single 6SN7 input with LED bias. Nothing changed at all. I'm happy.
https://production.diyaudio.com/community/index.php?posts/3400631/
https://production.diyaudio.com/community/index.php?posts/3400631/
Here is my favorite amp, very simple, easy to build, quite cheap, output ~ 3W, deadly quiet with noise 0.6-0.8mV. Sound is so sweet and It beats my 300B on midrange
Attachments
Last edited:
Interesting. It looks like one winding of the primary is simply acting as a feedback loop.
Feedback? Its a normal 50 percent between pentode and triode to me. Ultra linear concept. Evolve plz
Edit. I see now, its on G2. Sorry. Yes please?
Last edited:
Feedback? Its a normal 50 percent between pentode and triode to me. Ultra linear concept. Evolve plz
Edit. I see now, its on G2. Sorry. Yes please?
If two windings were in series and its center point were connected to G2 it could be UL, but they are in parallel.
- Home
- Amplifiers
- Tubes / Valves
- One more 4P1L SE