Consider 4P1L

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Consider 4P1L

Posted by andy evans (A) on October 26, 2015 at 05:31:07

In Reply to: New To SET world. Where to start. posted by altecboy on October 25, 2015 at 08:02:46:

You will get a mass of answers that will recommend you to use 2a3 or 300b output tubes. That's fine except:
- they are expensive and getting more so, and remember they need to be replaced as well
- they are low gain so you need 3 stages or a high gain input tube

I took the path of using PSE 4P1L outputs because:
- they sound pretty much as good - this is a DHT also
- they have gain of around 9 so you can use 2 DHT stages, e.g. 4P1L first stage as well
- they operate at 250v and 70mA for a pair (18W dissipation) so simpler PSU
- a pair in PSU uses a 3.5K OPT same as a 300b
- they are CHEAP and you can buy a lifetime supply for the price of one premium 300b.
- they can be used in filament bias which eliminates the cathode bypass cap

Research all this together with schematics at DIY Audio, thread "4P1L DHT Line Stage". And also same site, "One more 4P1L SE",

More information at www.bartola.co.uk including lots of technical details. Ale Moglia is an authority on all this. While on that site, look at his 01A Gen 2 preamp, which is the best I've ever heard. It's just stunning. And I've built several 26, 10Y, 4P1L etc. preamps myself.

4P1L DHT Line Stage (Open in New Window)

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Follow Ups Full Thread

Topic - New To SET world. Where to start. - altecboy 08:02:46 10/25/15 (17)

Maybe a Mullard... - Triode_Kingdom 08:55:50 10/27/15 (0)

RE: New To SET world. Where to start. - DAK 18:18:28 10/26/15 (0)

RE: New To SET world. Where to start. - Caucasian Blackplate 16:40:13 10/26/15 (0)

Budget? - Eli Duttman 14:20:26 10/26/15 (4)

1626/12V6 ?? nt - Frihed89 01:23:44 10/27/15 (3)

RE: 1626/12V6 ?? nt - Eli Duttman 09:21:07 10/27/15 (2)

RE: 1626/12V6 ?? nt - Al Noakes 08:10:34 10/28/15 (0)

I was just thinking... - Frihed89 14:59:30 10/27/15 (0)

RE: What skills do you have? - deafbykhorns 11:31:11 10/26/15 (0)

Consider 4P1L - andy evans 05:31:07 10/26/15 (0)

RE: New To SET world. Where to start. - howardnair@comcast.net 11:32:06 10/25/15 (6)

RE: New To SET world. Where to start. - altecboy 03:04:19 10/27/15 (5)

RE: New To SET world. Finally !!! - Tom B. 07:48:37 10/28/15 (0)

The 6J7/2A3 amp - Paul Joppa 18:18:36 10/27/15 (1)

Best Advice EVER! - Triode_Kingdom 21:16:28 10/27/15 (0)

RE: New To SET world. Where to start. - DAK 12:17:06 10/27/15 (1)

RE: New To SET world. Where to start. - deafbykhorns 16:42:31 10/27/15 (0)

Follow Ups

Consider 4P1L - andy evans 05:31:07 10/26/15 (0)

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