Warning About The Singlepower Extreme - Owners Please Read - Page 5

Thanks Kevin. Would you just wire the secondaries in parallel? 110 +110 and 6.3 + 6.3?

Best,

Paul

The "UPGRADED" transformers for the supra extremes is now known to be
the hammond 266PA14. Wired in the same awful way. Better. But still
not sufficient.

Nate. Thanks for the help with the wiring. I just wanted to be sure. The Edcor TX sounds like a near drop-in except that it will not fit underneath the transformer enclosure, not a deal breaker if it maintains or improves the sound quality... and makes the amp a good long term and safe keeper.

As I look through this thread and a couple other SinglePower "Lovefest" threads one thing that really stands out is how wildly different the same SP model can be on the inside. I think that I can see some progress in certain cases. He went from hand wired to PCB and from oddly wired PCB to more logical PCB layouts but it seems that he was very erratic, sometimes turning out a well built device, other times turning out odd or dangerous stuff. My amp looks pretty good except for the "power" transformer. Wiring is acceptable, rectifier has some heat transfer tape on the back side, caps look properly spec'ed for the relatively low voltage Extreme circuit. Maybe he named it the Extreme because he was pushing the transformer to an extreme condition :-)

Lets share our repair, mod, and rehabilitation findings and make this a really useful thread...

Transformer rating guidance

That is way to high of a high voltage. An extreme really wants to
be 150 to 180 volts rectified and filtered.

"There is an edcor transformer that is cheap that works.
EDCOR - XPWR039"

But.............


XPWR039
Rohs
Tube Amplifier Power Transformer
Power transformer from 120V or 240V, 50/60Hz. to dual 110V at 250mA and dual 6.3V at 4A.


So, the question might be--'cause I am ignorant--doesn't the Extreme need at least 6 A. Each 6080 is 2.5 amp X 2 = 5.0 + 6SN7 = 0.6. Total = 5.6A current draw in an extreme?

Thanks much.

Also

"The "UPGRADED" transformers for the supra extremes is now known to be the Hammond 266PA14. Wired in the same awful way. Better. But still not sufficient."

266PA14

14V @ 6A

7V @ 12A

This would seem more like it.

Is the Edcor an option at 4A?


Thanks for guidance to all.

dual secondaries in parallel === 6.3 volts at 8 amps.
dual high voltage in parallel === 110 volts at .5 amp.

Thanks for reply

Thanks, Kevin--nice of you to help the weak.

If one of ordinary skill in field can easily replace transformer--and wire it properly (can any tech do this--do you think based on pictures on the site?), which of the two transformer would you recommend.

The EDCOR has better aesthetic appeal, but if the Hammond upgrade is the one--please advise the best option and I may simply move forward and order. May as well get the fix over with ASAP.

BTW--what do you have on yours--looked more like EDCOR.

Much thanks.

If I can ask for the Platinum owners, should we be concerned with our tranny issues? I figure we need the bleeder loads on the caps.

That sentence caused me to do a double take.

The Hammond would NOT be a suggested upgrade. That transformer is what was sold as an upgrade by Singlepower. It still is wired using the primary as the feed to the high voltage section. Not very safe and it pulls current from the secondaries.

The EDCOR is what Kevin has come up with for a reasonable cost replacement that is SAFE. Be aware that EDCOR does not stock any transformers. Everything is a custom build for them. Once an order is placed it can take 3-4 weeks for them to deliver.

The transformer used in Kevin's Extreme is a custom unit made by Electraprint. I believe it costs about twice as much as the EDCOR and takes up more real estate.

If you can easily access the screws that hold the transformer cover in place, changing out the transformer should not be too big a problem. If you have a circuit board Extreme, disassembly is a PITA. It will take awhile. You will have to unsolder all the tube sockets and remove most of the controls, switches and connectors. You may have to drill some more holes to fit the mounting pattern of the new transformer. Parts cost may not be too much, but labor cost will be more.

Thanks for that Phil...made me laugh this morning

The other 266pa14 hammond transformer is wrong for the same reasons as the
other transformer. Way underpowered and unsafe when one of the primarys is
used as a secondary.

Transformative Guidance

I have the 2007 revision A board. It appears that I can get under the board and with a needle nose or small wrench get to the screws holding the transformer cover, assuming the bolt comes of easily from the screw. Veteran techs are clever on how they need to do these things.

If not, I was thinking of telling the tech (if required) to drill two clean holes on the top of the Extreme, which can be covered afterward with black plastic snap-in-plugs, or left as vent holes. I have a mind to do what Keven did--simply leave the cover off, like the MPX3 and PPX3 when they first came out.

When I call the tech I can give him info for ordering, or order myself (he does not charge more for parts I source).

Would you know the specifications and Model# of the Transformer from Electroprint?
Maybe Kevin or you could share this info.
What should the spec. be for primary(s) and secondaries be?

True, if the tranny can be operated on without major surgery, the cost will be far less. Simple R&R.

Thanks+++

Might also ground ground the RCA inputs (see pic)?

skylabs unit. Same burned up transformer. More lousy/cold solder joints
http://gilmore.chem.northwestern.edu/skylab-1.jpg
http://gilmore.chem.northwestern.edu/skylab-2.jpg
http://gilmore.chem.northwestern.edu/skylab-3.jpg
http://gilmore.chem.northwestern.edu/skylab-4.jpg
http://gilmore.chem.northwestern.edu/skylab-5.jpg
http://gilmore.chem.northwestern.edu/skylab-6.jpg
http://gilmore.chem.northwestern.edu/skylab-7.jpg
http://gilmore.chem.northwestern.edu/skylab-8.jpg
http://gilmore.chem.northwestern.edu/skylab-9.jpg
http://gilmore.chem.northwestern.edu/skylab-10.jpg
http://gilmore.chem.northwestern.edu/skylab-11.jpg

after having a number of units i now notice that the holes for
the transformer cover and the transformer are never in the same
place from unit to unit.

Have not seen a balanced extreme yet, but with lots of pictures
of mpx3 extremes, ppx3 extremes, and supra extremes i have to
conclude that every single transformer is burning up.

Is this one of the earliest PCB models?
Anyone know when he switched from point to point to PCB?