Home » Audio » Thermionic Emissions » Douglas, Damir, I did some more work on the 300bPP amps
Re: 300bPP amps [message #9422 is a reply to message #9416] Sun, 18 December 2005 20:06 Go to previous messageGo to next message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
Hey-Hey!!!,
While I might have done the front end a bit differently, simple is good.

Did you need to DC the 6SN7's heater? I have run 6SL7>6SN7>Finals and used AC heaters w/o hum. Just curious, as another part of the eq'n is that feeding a big cap input DC filter has usually made some other noise.

I've played with the phase splitter autoformer. I always go back to the balanced drive version with the LTP doing the phase splitting and a high leakage L choke. Maybe a better phase splitting choke is the key...:)

If multi-grid tubes didn't keep me so entertained, I'd go and try a PP DHT amp. Cathode driven...:) PP 6CK4>2A3>IT>845

maybe not-so-simple can be good too.
cheers,
Douglas

Re: 300bPP amps [message #9423 is a reply to message #9422] Sun, 18 December 2005 23:10 Go to previous messageGo to next message
Tre' is currently offline  Tre'
Messages: 34
Registered: May 2009
Baron
I probably don't need the DC filament. Force of habit. When I built my preamp with the outboard power supply and the DC filaments. I guess I just stayed in that same mode building the front and it's outboard power supply. I should try AC.

Thanks for looking....Tre'

typeO [message #9424 is a reply to message #9423] Sun, 18 December 2005 23:18 Go to previous messageGo to next message
Tre' is currently offline  Tre'
Messages: 34
Registered: May 2009
Baron
That should have been "I just stayed in that same mode building the front END and it's outboard..."

Re: What would happen if....... [message #9425 is a reply to message #9421] Mon, 19 December 2005 05:54 Go to previous messageGo to next message
Damir is currently offline  Damir
Messages: 1005
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Illuminati (2nd Degree)
In principle yes, but I never tried those clever ("Ultrapath" tricks, sorry...

Sweet! [message #9427 is a reply to message #9412] Mon, 19 December 2005 08:48 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18723
Registered: January 2001
Illuminati (33rd Degree)


Last picture [message #9433 is a reply to message #9412] Tue, 20 December 2005 16:50 Go to previous messageGo to next message
Tre' is currently offline  Tre'
Messages: 34
Registered: May 2009
Baron
I needed something to set the amps on. I had the fake marble so I got some 2x2s .......

Tre'


Wrong URL, Sorry [message #9434 is a reply to message #9433] Tue, 20 December 2005 16:54 Go to previous messageGo to next message
Tre' is currently offline  Tre'
Messages: 34
Registered: May 2009
Baron
.

Looks great! [message #9437 is a reply to message #9434] Wed, 21 December 2005 08:52 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18723
Registered: January 2001
Illuminati (33rd Degree)


Re: typeO [message #9476 is a reply to message #9424] Tue, 03 January 2006 19:21 Go to previous message
PakProtector is currently offline  PakProtector
Messages: 935
Registered: May 2009
Illuminati (2nd Degree)
Sometimes it's hard to sidestep quiet habits. I was laying out a pre, and in my haste decided to wire up the 5687 cathode follower faux pentode with AC heaters.

The parts truck was late delivering my late-ordered parts for the DC supply, and I was impatient. I was quite suprised when it was quiet on AC. That's a first for a 5687 pre for me.
cheers,
Douglas

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