6B4G - The Resurrection Shuffle

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Cressy Snr
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#346 Re: 6B4G - The Resurrection Shuffle

Post by Cressy Snr »

Audio cct with amendments:
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Paul Barker
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#347 Re: 6B4G - The Resurrection Shuffle

Post by Paul Barker »

Called to hear this again, in it’s latest form. considerable improvement. shocking good amp now. Shoddy!
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Cressy Snr
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#348 Re: 6B4G - The Resurrection Shuffle

Post by Cressy Snr »

Paul Barker wrote: Mon Jan 01, 2018 9:43 pm Called to hear this again, in it’s latest form. considerable improvement. shocking good amp now. Shoddy!
Thanks Paul.
Nice to see you yesterday and interesting to hear about the old DIY American scene and the Triodeel message board and the VSAC shows. It is very interesting for me to find out that the sort of thing I've built is actually in the spirit of those old SE revivalist guys.

Three stages is now somewhat old fashioned, in terms of how you build a great SET amplifier, and driving a 2A3 with a 7 pin EL84 equivalent valve is firmly in sledgehammer and walnut territory. Nevertheless, it's a better sound than I've had from any amp in my system; far - and I do mean far outstripping any hi-gm pentode driver, 2 stagers or Monkey amps I've had.

The sound characteristics it has are more like a high gain, British battery valve driving PX4s/2P or something like that - all big toned and detailed but not bright or artificial. Just the sort of thing that floats my boat.

Anyway the path I want to go down is a lot clearer now, and it will probably end in the form of a three stage SET PX4, either NOS or KR globe type.
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#349 Re: 6B4G - The Resurrection Shuffle

Post by IslandPink »

Good work Steve. Maybe made the wrong choices in my three-stager a few years ago ?
If I remember correctly it was resistor-loaded ECC40 direct-coupled into 2A3 'stood' on something like a 12k resistor, and choke-loaded with 55H Purvine choke ; then cap-coupled ( copper PIO ) into the KR 300B. It did sound good but it was just subtle +/- against the C3m driver. Looking back after the experiences with DHT filament supplies, there's a lot that can go missing with something non-optimal there, for the 2A3's I used some Thorsten-style DIY ones as per the 'Ladyday' amp mods, which I've tried since and aren't as good as the Lehane ones. Having an IDHT in the 2nd valve position does avoid some of these trade-offs, in the bass region especially. Course since then I moved on to 4P1L as the driver which was better than the C3m .... it woul dbe nice to compare some time, in the same system.
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andrew Ivimey
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#350 Re: 6B4G - The Resurrection Shuffle

Post by andrew Ivimey »

I'm in a bar at Reading Station.....hoping that Anna will notice my glass is empty. I can't remember the driver valve but having tried both of Thorsten's Monkeys I settled on the one with 300 bs but with 50 volts or so drop in HT and using mercury rectifiers 83, using 2a3s with the appropriate heater transformers which can also take px4s if I revert to a dropper resister on the original windings of a WAD 300b pse, that's the chassis mono blocked I'm using. After extensive testing I prefer overpowering cheap Chinese 2a3s keeping the monster 2a3s for best...but never getting round to using them. (A bit like the px4s) .

If that doesn't make much sense I'll blame the lack of pangalactic gargelblasters. .. come on Anna!
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#351 Re: 6B4G - The Resurrection Shuffle

Post by ed »

with a bit more attention to the meter it could have passed for Vogon poetry
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andrew Ivimey
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#352 Re: 6B4G - The Resurrection Shuffle

Post by andrew Ivimey »

Today is my 64th birthday.

'...only the second worst poetry in the galaxy...' Hooray for Paul Neil Melne-Johnson except that none of his poetry survived...
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
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pre65
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#353 Re: 6B4G - The Resurrection Shuffle

Post by pre65 »

[quote="andrew Ivimey" post_id=154012 time=1514927594 user_id=22]
Today is my 64th birthday.

/quote]

Happy birthday you youngster. :lol:

Before too long Audio Talk will have to be renamed Old Codgers Talk. :roll:
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andrew Ivimey
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#354 Re: 6B4G - The Resurrection Shuffle

Post by andrew Ivimey »

But will be quite unable to hear anything!
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#355 Re: 6B4G - The Resurrection Shuffle

Post by jack »

andrew Ivimey wrote: Tue Jan 02, 2018 9:13 pm Today is my 64th birthday.

'...only the second worst poetry in the galaxy...' Hooray for Paul Neil Melne-Johnson except that none of his poetry survived...
It's creeping up on all of us. I've a big one coming up soon.

Pfhnar!
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Cressy Snr
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#356 Re: 6B4G - The Resurrection Shuffle

Post by Cressy Snr »

Snubber network, consisting of 100nF in series with 1K, has now been installed across the choke.
Amp is now very quiet in terms of the mechanical noise coming from from the powered iron; certainly quieter than anything else I've built over the years.

A little bit more music is being let through. OK its subtle but there, and is more of an increase in the sense of an easy, natural presentation, than any sort of "hi-fi" boost in the level of detail.
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#357 Re: 6B4G - The Resurrection Shuffle

Post by Cressy Snr »

PSU with choke snubber added:
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#358 Re: 6B4G - The Resurrection Shuffle

Post by Cressy Snr »

And finally with star earthing throughout:
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pre65
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#359 Re: 6B4G - The Resurrection Shuffle

Post by pre65 »

Steve, you were always such a devotee of bus bar earthing.
The only thing necessary for the triumph of evil is for good men to do nothing.

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Cressy Snr
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#360 Re: 6B4G - The Resurrection Shuffle

Post by Cressy Snr »

pre65 wrote: Thu Jan 04, 2018 6:44 pm Steve, you were always such a devotee of bus bar earthing.
Yes, I've always built amps with the power supply at the side of the chassis, so bus bar earthing was the easiest way to distribute the ground connection. This one, with the rectifier and choke in the centre, flanked by a pair of capacitor banks was screaming for star earthing, so that's what it got.....eventually. :)

Not bad for something that was built with what I had lying around, what valves I had left and some scrounged output transformers.
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