Restacking An Output Transformer.

We all start somewhere
User avatar
pre65
Amstrad Tower of Power
Posts: 19550
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex

#31 Re: Restacking An Output Transformer.

Post by pre65 »

Well done Steve, a pat on the head for a successful outcome. :)
Life is what happens to you while you're busy making other plans. John Lennon

G-Popz THE easy listening connoisseur. (Philip)
User avatar
Ali Tait
Eternally single
Posts: 4151
Joined: Fri Jun 08, 2007 8:10 pm
Location: Galashiels

#32 Re: Restacking An Output Transformer.

Post by Ali Tait »

Grand job Steve!
simon
Eternally single
Posts: 4710
Joined: Thu May 24, 2007 11:22 am
Location: People's Republic of South Yorkshire

#33 Re: Restacking An Output Transformer.

Post by simon »

Great result Steve. I've really enjoyed reading this thread, though not had chance to read the Turner Audio pages yet. What make are/were the PP OPTs? I must have missed this.
User avatar
Nick
Site Admin
Posts: 13656
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#34 Re: Restacking An Output Transformer.

Post by Nick »

If you haven’t already, I would loosen the bolts and let the lams clamp together with the amp running then tighten up again (while running).
Little known fact, coherent thought can destructively interfere with itself leaving no thought at all, that’s why I prefer incoherent thought.
Cressy Snr
Loony Bin!
Posts: 9554
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#35 Re: Restacking An Output Transformer.

Post by Cressy Snr »

simon wrote: Sat May 15, 2021 5:46 pm….What make are/were the PP OPTs? I must have missed this.
They were the Danburys I had when I had the push pull amps.
“The sound you love today may not be the sound you love tomorrow, and with tube circuits you can continually retune your gear to what reflects your current vibe...so you can get even down deeper into your truth.” (Harvey Rosenburg.)
Cressy Snr
Loony Bin!
Posts: 9554
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#36 Re: Restacking An Output Transformer.

Post by Cressy Snr »

Nick wrote: Sat May 15, 2021 5:54 pm If you haven’t already, I would loosen the bolts and let the lams clamp together with the amp running then tighten up again (while running).
Cheers Nick,
I’ve already done that with the aid of a bloody great long screwdriver, after noting your earlier post.
Last edited by Cressy Snr on Sat May 15, 2021 10:23 pm, edited 1 time in total.
“The sound you love today may not be the sound you love tomorrow, and with tube circuits you can continually retune your gear to what reflects your current vibe...so you can get even down deeper into your truth.” (Harvey Rosenburg.)
User avatar
IslandPink
Social Sevices have been notified
Posts: 8830
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#37 Re: Restacking An Output Transformer.

Post by IslandPink »

Sorted - respect Due !
Stouffer.jpg
Stouffer.jpg (6.71 KiB) Viewed 1277 times
"Peridots and periwinkle, blue medallions Gilded galleons spilled across the ocean floor" ( Mitchell )
User avatar
Greg
Shed dweller
Posts: 2975
Joined: Wed May 23, 2007 11:14 am
Location: Bristol, UK

#38 Re: Restacking An Output Transformer.

Post by Greg »

Great outcome, Steve. Domestic peace, I trust, after you ‘interfered’ with the amp?
Cressy Snr
Loony Bin!
Posts: 9554
Joined: Wed May 30, 2007 12:25 am
Location: South Yorks.

#39 Re: Restacking An Output Transformer.

Post by Cressy Snr »

Greg wrote: Sat May 15, 2021 8:44 pm Great outcome, Steve. Domestic peace, I trust, after you ‘interfered’ with the amp?
I think I got away with it.
“The sound you love today may not be the sound you love tomorrow, and with tube circuits you can continually retune your gear to what reflects your current vibe...so you can get even down deeper into your truth.” (Harvey Rosenburg.)
User avatar
Paul Barker
Oooo, Roberts Radio's sound nice
Posts: 7726
Joined: Mon May 21, 2007 9:42 pm

#40 Re: Restacking An Output Transformer.

Post by Paul Barker »

simon wrote: Sat May 15, 2021 5:46 pm Great result Steve. I've really enjoyed reading this thread, though not had chance to read the Turner Audio pages yet. What make are/were the PP OPTs? I must have missed this.
Turner made/makes? and sold them.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Paul Barker
Oooo, Roberts Radio's sound nice
Posts: 7726
Joined: Mon May 21, 2007 9:42 pm

#41 Re: Restacking An Output Transformer.

Post by Paul Barker »

Someone needs to capture the relevant transformer and choke teachings.... before the pages are lost. I find old search engines like Way back Machine have often found nothing, that I know existed. I tried marrying his teachings with RDH3 but Id not have gleaned the data without Turners interpretation.

That £70 book linked earlier is more likely not as in depth but might be presented better with classy illustrations and step by step photographs. probably though not worth the cost.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Paul Barker
Oooo, Roberts Radio's sound nice
Posts: 7726
Joined: Mon May 21, 2007 9:42 pm

#42 Re: Restacking An Output Transformer.

Post by Paul Barker »

I spoke to Turner at length perhaps 15 years ago. I got the impression he is biased push pull, not open for discussion. Hes chosen a different path in audio to me. Probably believed I was deluded about an amp like Steves built.

Such good news those push pull transformers have resulted in better than the ones you started with Steve. Id have expected some early bass roll off. Id have left core alone, wound a choke and found a good cap. primary inductance would be much more. Parafeed is not a second rate SE version. Its different but very nice and was more common in the really early days before matching transformers, the speaker was parafed from the amp raw. Then when matching transformers rose up parafeed was carried on, but died off until Paul Joppa (is that the man?) used it with much popularity.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
rowuk
Old Hand
Posts: 368
Joined: Sun Jun 01, 2014 2:50 pm
Location: Germany

#43 Re: Restacking An Output Transformer.

Post by rowuk »

What would happen if we used the Parafeed cap as part of a crossover? Seems to me that it would be 6dB/8va for free! Would that also not reduce the demands on the choke? With another cap at the input of the amp, we have 12dB for free.
Whenever I feel blue, I start breathing again.
Wolfgang
Old Hand
Posts: 225
Joined: Mon May 07, 2018 3:08 pm

#44 Re: Restacking An Output Transformer.

Post by Wolfgang »

What would happen if we used the Parafeed cap as part of a crossover?
An issue could be that the OPTs primary has a much higher inductance than what would be needed for L for using the OPT as part of x-over filter. Personally I wouldn't trust this kind of operation -even if it were possible - because of all kind of unforseeable (phase) issues etc . Another thing is that the parafeed OPT and a typical 2nd order passive LCR filter might work differently despite the fact that both are connected to ground through a cap/cap and resistor.
Parafeed is not a second rate SE version
And let's not forget that even if we use an air gap and have no saturation of the core for the DC current upto a certain amount we still cannot use the best possible core material for best performance.
User avatar
Nick
Site Admin
Posts: 13656
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#45 Re: Restacking An Output Transformer.

Post by Nick »

we still cannot use the best possible core material for best performance
Why not?
Little known fact, coherent thought can destructively interfere with itself leaving no thought at all, that’s why I prefer incoherent thought.
Post Reply