Hello everyone,
I wonder if anyone here had experiance with fixing or remaking of Pioneer output transformers, I would like to duplicate their design without destroing one of my trasformers. As far as I can tell this is the best transformer design from the 60's that I have bumped into until today (compared against Fisher, scott, kenwood etc.).
Multi thin wire primery, no bobbin, highly laminated, thin plastic insulation between the layers, silicon steel core and so on and on...
Thank you very much.
glass_painter
I wonder if anyone here had experiance with fixing or remaking of Pioneer output transformers, I would like to duplicate their design without destroing one of my trasformers. As far as I can tell this is the best transformer design from the 60's that I have bumped into until today (compared against Fisher, scott, kenwood etc.).
Multi thin wire primery, no bobbin, highly laminated, thin plastic insulation between the layers, silicon steel core and so on and on...
Thank you very much.
glass_painter
Glass Painter,
That is just wonderful. Can you tell me more about this output transformer. Is it meant for SE or UL? What is the spec? I too am looking to duplicate some great transformer for my EL84 UL amp.
If I can have the specification, I can send them to my local trans winder. I'll be watching this thread for more information.
That is just wonderful. Can you tell me more about this output transformer. Is it meant for SE or UL? What is the spec? I too am looking to duplicate some great transformer for my EL84 UL amp.
If I can have the specification, I can send them to my local trans winder. I'll be watching this thread for more information.
Pioneer transformers
Hi,
I am talking specificly about the AT6123 output transformer tipycal of the PP 6BQ5 to 7868 units. it is a regular PP unit not UL.
I have pioneer SM-83 amp and after replacing the tubes, caps, the resistors in the signal path and the electrolitics with good quality parts the amp sounds fantastic.
I have a lot of material for building transformers and would like to build some more based on this design. Hopefuly someone can help with the wire schema so that I will not have to destroy the spare unit I have got.
If you want to wind your own units, I think that a good place to start would be "turner audio" he has atransformer design there that I think can be converted to 6BQ5 design just by going from 44 mm tongu EI material to 25 mm, primery wire to size 0.22 instead of 0.36 and secondary wire size 0.65 mm instead 1 mm all the other aspects of the design (I E number of turns, number of layers etc.) can be unchanged.
Please let me know if you have tryed and what ware the results.
Good luck.
Glass_painter
Hi,
I am talking specificly about the AT6123 output transformer tipycal of the PP 6BQ5 to 7868 units. it is a regular PP unit not UL.
I have pioneer SM-83 amp and after replacing the tubes, caps, the resistors in the signal path and the electrolitics with good quality parts the amp sounds fantastic.
I have a lot of material for building transformers and would like to build some more based on this design. Hopefuly someone can help with the wire schema so that I will not have to destroy the spare unit I have got.
If you want to wind your own units, I think that a good place to start would be "turner audio" he has atransformer design there that I think can be converted to 6BQ5 design just by going from 44 mm tongu EI material to 25 mm, primery wire to size 0.22 instead of 0.36 and secondary wire size 0.65 mm instead 1 mm all the other aspects of the design (I E number of turns, number of layers etc.) can be unchanged.
Please let me know if you have tryed and what ware the results.
Good luck.
Glass_painter
I think this is the link:
http://www.turneraudio.com.au/htmlwebpgs02/outputtrans.htm
Patrick Turner is friendly and approachable. He posts on the newsgroup "Rec Audio Tubes" (at least he was when I last checked).
http://www.turneraudio.com.au/htmlwebpgs02/outputtrans.htm
Patrick Turner is friendly and approachable. He posts on the newsgroup "Rec Audio Tubes" (at least he was when I last checked).
Please check the Hashimoto Web Site. I understand that Pioneer subcontracted the manufacture of these AT6123 to them in the 60's.
One look at the physical aspects of the AT6123 and the Hashimoto products look the same.
One look at the physical aspects of the AT6123 and the Hashimoto products look the same.
Tom:
I had an A500 and the frequency response was phenomenal. Especially the Mid's and High's.
No wonder I always loved this amplifier. Sold it a 3 years ago to a very happy owner.
Now I understand why the A500 was so musical, thanks for the post.
Freed transformers had the secret sauce
I had an A500 and the frequency response was phenomenal. Especially the Mid's and High's.
No wonder I always loved this amplifier. Sold it a 3 years ago to a very happy owner.
Now I understand why the A500 was so musical, thanks for the post.
Freed transformers had the secret sauce
Actually, I was mistaken, it was a TA5000 - though it may have been the same transformer as an A-500. Response was -3 dB at 80 KHz, phase was flat (-10 deg) to 100 KHz. Phenomenal transformer. Heath AA-50 actually went to 200 KHz and was still above -3 dB. Dynaco A-420 did 40 KHz at -3dB. Still have to find the data n that Pioneer...
I believe that the TA5000 used the 7355 tube as the A500 and the same Freed OPT's but in a vertical mounted configuration.
My friend owns an A700 and the stock output transformers are dreadful sounding.
Actually I replaced the OPT's on an A700 11 years ago with a pair of Hammond 1620 and the improvement over the stock transformers was absolutely phenomenal.
Hammond OPT's are OK sounding as compared to stock vintage, yet with the 7591A the 1620 works very well.
My friend owns an A700 and the stock output transformers are dreadful sounding.
Actually I replaced the OPT's on an A700 11 years ago with a pair of Hammond 1620 and the improvement over the stock transformers was absolutely phenomenal.
Hammond OPT's are OK sounding as compared to stock vintage, yet with the 7591A the 1620 works very well.
The Hammond 1620 was near the bottom in my testing, though some PA and most console transformers were worse. It had a nasty 2X peak in impedance at 40 KHz when using 8 Ohms, but was reasonably good with 4 Ohm tap terminated.
The Pioneer did 60 KHz at -3 dB, Fisher 500B and 500C did 70 and 80 KHz.
One of these days I'll get around to getting all the data into a presentable (hopefully comprehensible...) form and putting it on my web site. And a friend has a Citation II transformer I can add to the list.
The Pioneer did 60 KHz at -3 dB, Fisher 500B and 500C did 70 and 80 KHz.
One of these days I'll get around to getting all the data into a presentable (hopefully comprehensible...) form and putting it on my web site. And a friend has a Citation II transformer I can add to the list.
Great information, and thanks so much for sharing.
My ears have always favored vintage HiFi equipment, and it is wonderful that you have measurements that prove these designs and the level of craftmanship was excellent.
Now I am going to measure the OPT's on the Olson AM-240 amplifier I have as the sound from this one is also very detailed.
I will post the results when I have them.
My ears have always favored vintage HiFi equipment, and it is wonderful that you have measurements that prove these designs and the level of craftmanship was excellent.
Now I am going to measure the OPT's on the Olson AM-240 amplifier I have as the sound from this one is also very detailed.
I will post the results when I have them.
that's a 1 inch center leg, x 1 1/8 core, bobbins are available...
there are also build guides from dissident audio....6L6 Push Pull
there are also build guides from dissident audio....6L6 Push Pull
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.