A while back, I was looking for a pair of output transformers for a spud amp build. I came across a new line of hi-fi OT's from Musical Power Supplies. I did a search for them here and did not find anything. I had built a bunch of guitar amps with Matt's OT's in the past, and had been very pleased with them. I ordered a pair a little less than a month ago and got them yesterday.
They are the same size as the Edcor GXSE10's, though vertical instead of horizontal, and the laminations are thicker at 1 1/4" vs 1" for the Edcors. There's no ultralinear tap, though there are 4 and 8 ohm output options.
The end bells are off and painted.
They are the same size as the Edcor GXSE10's, though vertical instead of horizontal, and the laminations are thicker at 1 1/4" vs 1" for the Edcors. There's no ultralinear tap, though there are 4 and 8 ohm output options.
The end bells are off and painted.
Yes, these transformers are made for guitar or old tube radio equipment building.
OT10SE-VC87 Single Ended Output Transformer 12VA 5K,7Kohm:4/8/16 60mA | eBay
80Hz...10kHz
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Oh no, theses are different than the guitar OT's. I've built a bunch of Champish amps with those. The HF line has a claimed frequency response of 40Hz to 20kHz. We'll see about that when I get the amp built.
This is their website Musical Power Supplies, Inc. - Home
They are based in Lake Saint Louis, but trafos say "Origin: Mexico".
They are based in Lake Saint Louis, but trafos say "Origin: Mexico".
I bought some transformers from Musical Power Supplies back when they were in Florida. At that time some of their transformers were made in house (Florida). The lower priced transformers were made in one of the Caribbean Islands. I have not purchased any since they packed up and moved.
They seem to use the same business model, some transformers are made in Mexico (previously made in Asia), while others are US made.
I looked at these recently for low buck guitar amps, but they are in the same price range as Edcor for similar transformers of a similar weight. I still may try them if I decide to proceed in that direction.
They seem to use the same business model, some transformers are made in Mexico (previously made in Asia), while others are US made.
I looked at these recently for low buck guitar amps, but they are in the same price range as Edcor for similar transformers of a similar weight. I still may try them if I decide to proceed in that direction.
Those prices are so low, im skeptical how they actually make a profit. It would be interesting to do some A B C comparison testing using the same amp, by swapping out with equivalent Hammond and Edcor and Antek units and printing off the same tests for each, and recording some MP3 files of each model through a dummy load to hear anything different.
While on the subject of cheap transformers these caught my eye 1pair 3.5K Amorphous Single-ended Output Transformer for 6P6P KT66 2A3 tube amp | eBay
I dunno - using a conductive house clamp around the coil doesn't look like a good idea...
Correction - they're using the hose clamp to hold the cores together, and that's OK.
I've been wanting to try some transformers from MPS for a while. I have one of their power transformers, and I may pony up for a pair of the 5k HiFi SE transformers
Correction - they're using the hose clamp to hold the cores together, and that's OK.
I've been wanting to try some transformers from MPS for a while. I have one of their power transformers, and I may pony up for a pair of the 5k HiFi SE transformers
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Interesting it says double C core but I only see one core. I like the ingenuity and resourcefulness though the guy re-using the cores.
The link says Amorphous.
Then it says:
"The use of imported second-hand amorphous alloy sheet winding"
I never knew that a sheet of material was 'amorphous'.
Perhaps something lost in the translation from Chinese to English.
I am not a materials expert.
But I never desired to purchase any amorphous core.
I missed that boat of opportunity.
Then it says:
"The use of imported second-hand amorphous alloy sheet winding"
I never knew that a sheet of material was 'amorphous'.
Perhaps something lost in the translation from Chinese to English.
I am not a materials expert.
But I never desired to purchase any amorphous core.
I missed that boat of opportunity.
It looks like genuine amorphous core, although I wouldn't by this. Looks like a 1W OPT @25Hz core at best. This is why it's cheap 🙂
And you are right. I bought and measured them. You do not need 25 Hz from a small amp, so for 2-3W it would be good.
Got the spud amp built, 3.5W output. The -3dB points are at 30 Hz and 30 kHz, though there is a bit of distortion under 40 Hz. The tubes are 6T9 so it's semi-comparable to my 6SL7/6V6 SE amp with Edcor GXSE-10 OTs. At similar volume, I can't tell any significant differences.