Dynaco Stereo 35 replacement output transformers
- Thread starter guitargrump
- Start date
JustMe2023
Member
I asked Thermionic Lab a few days ago about their ST-35 transformers because they are oversized and supposedly don't fit, and they said,
Hello,
thank you for your kind suggestion and your time to write.
Making drop in replacements is scheduled for the future.
Regards
Thermioniclab
Hello,
thank you for your kind suggestion and your time to write.
Making drop in replacements is scheduled for the future.
Regards
Thermioniclab
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JustMe2023
Member
One of my issues is that I have no ability to test the performance of any transformers, so taking a manufacturer's word for it isn't a good idea for me. I would need proven, drop-in replacements. Edcor has a set on their site. Anybody know anything about them? https://edcorusa.com/collections/dynaco/products/stereo-35-st-35
Can you be more specific about what you're trying to accomplish? Do you currently have a ST-35 with defective transformers? Or is it something else?
Jack
JustMe2023
Member
I was considering building (more likely) or rebuilding (less likely) a ST-35. I currently do not own one.
drtool
It might get loud In Houston
I did, no answer.
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JustMe2023
Member
Ditto.
Have you tried https://store.triodestore.com/z517wadyoutr.html ?
JustMe2023
Member
Yes. OPTs currently not available for purchase. One page says the kits have been discontinued, yet I added a kit to my cart from another page. I don't like their kit though.
JustMe2023
Member
Response from Musical Power Supplies:
I’m working on an ST-35 Output transformer with some full load frequency response tests underway this month.
Right now it will be set up as 8K x 4/8 ohm with 25% UL taps and a para-coupled winding process as Dynaco used. Not sure yet where the full power low end roll off will be until testing is done. We are comparing directly to an OEM ST-35 transformer and the current test is basically the same size and footprint.
I have not taken a shot at the PT to date. That’d be after the OT is done.
I’m working on an ST-35 Output transformer with some full load frequency response tests underway this month.
Right now it will be set up as 8K x 4/8 ohm with 25% UL taps and a para-coupled winding process as Dynaco used. Not sure yet where the full power low end roll off will be until testing is done. We are comparing directly to an OEM ST-35 transformer and the current test is basically the same size and footprint.
I have not taken a shot at the PT to date. That’d be after the OT is done.
JustMe2023
Member
It looks like he actually is cloning it, with an original in hand, complete with test results. Good news indeed. I haven't committed to this project yet due to time and money, but step 1 is to find the parts. Step 2 is to save money to buy them. Step 3 is to find the time to build it.
Lavane
Lunatic Member
Out of all the amps I've built so far, I did find the ST-35 to be the most tedious due to the small shallow chassis. I just wish Dynakit sold these kits with solid core hookup wire instead of the stranded wire they supply. I was about out of hookup wire at the time and went ahead and used the stranded wire. About a 1/3 of the way through I wished I had waited to order solid core wire.
JustMe2023
Member
Q: Will you be restocking the ST-35 bias control upgrade kit?
Q: Will you be restocking the ST-35 power and output transformers?
Reply from DynaKit:
We expect to have both these products back in stock by next week.
We have a list right now for customers wanting to purchase one of our ST-35 Kits.
To be added to this list I would just require your full contact & shipping information plus order details.
We will only have stock on the Nickel plated chassis version of our ST-35 Kit. We do have stock on our optional top vented covers and expect to also have stock on our ST35-BCU bias control kit next week.
Regards,
Kevin D.
Will you be restocking the ST-35 bias control upgrade kit?
Will you be restocking the ST-35 power and output transformers?
I can relate to that. I just built a small Chinese EL84 amplifier kit, and it was pretty cramped inside. The small size is one thing that appeals to me though.
Q: Will you be restocking the ST-35 power and output transformers?
Reply from DynaKit:
We expect to have both these products back in stock by next week.
We have a list right now for customers wanting to purchase one of our ST-35 Kits.
To be added to this list I would just require your full contact & shipping information plus order details.
We will only have stock on the Nickel plated chassis version of our ST-35 Kit. We do have stock on our optional top vented covers and expect to also have stock on our ST35-BCU bias control kit next week.
Regards,
Kevin D.
Will you be restocking the ST-35 bias control upgrade kit?
Will you be restocking the ST-35 power and output transformers?
I can relate to that. I just built a small Chinese EL84 amplifier kit, and it was pretty cramped inside. The small size is one thing that appeals to me though.
Lavane
Lunatic Member
Good to hear the iron will be back in stock soon. The stranded wire was the worst part really. I don't like using it when 3 or more wires are going to a single 9 pin solder eye. But once done it became my favorite amp. I did recently add the bias board kit I had laying around for awhile. Its easy to add on to an existing amp. It has multi turn trim pots too.
Attachments
I use the 22ga solid PVC wire from Antique Electronic Supply for almost everything. It's tinned, easy to strip and solder, and the insulation doesn't melt unless you actually touch it with the iron. They even sell it in multi-color kits of shorter lengths, so you can build an entire amp without spending $100 for wire. This is just simply the best wire of its type I've ever used.
