UTM INDUSTRY audio transformers - from Poland - EU
- Thread starter Whoops
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Help Support GroupDIY Audio Forum:
I will try it out in my 4in1 mic pre here at groupdiy I will post measurmentsPlease let us know what you think of it when you have it, it will be my next order as well
warpie
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I ordered transformers for a Vari-Mu a month ago, fedex are slow though… no transformers yet
Over a month from Poland to Sweden? Wow!
It really has to be a new record.. I think I'll have to call them again on monday. Parcel has not moved since Dec 10th. Thankfully Its not for a customers project but for myself.
I checked the FedEx status. They were trying to deliver your package on Friday, 10 December 2021. 3 days after we ship them.I ordered transformers for a Vari-Mu a month ago, fedex are slow though… no transformers yet
But the reason was: "Customer not available or business closed".
Probably I have to contact FedEx add ask to try again.
Those companies are fast but I had the same problem with DHL, they didn’t left a note, call or warning they tried to deliver it so I couldn’t know and the parcel was sent back, I really dislike those companies and prefer regular mail, they always leave a Note
ruffrecords
Well-known member
I agree these inductances are too low. For comparison the Carnhill VRB2291 ( 9K6:600) has a measured primary inductance of 106H.
Cheers
VTB2291 has an EI57 core, while UTM3515 has an EI41. This could be a reason.
I had a similar problem recently. I needed urgently a USB extender, so ordered via Amazon, for overnight delivery..
2 days later I got a message from Amazon saying the driver had tried to deliver the parcel at 1.06 AM and there was nobody! Of course I was home.
The guy had just lied so he could be paid normally. They don't if they deliver late.
I know these guys have a harrassing job, but I hate it when they lie. They also do it often when they don't find the address, they just say they found nobody home.
ruffrecords
Well-known member
The UTM3515 winding is PRI: 1260+1260, SEC: 252+252. Serial 2 serial connection. DNE=0.13mm.
What do you think?
Hi igs,
thanks for joining this thread, it's great to be able to have more info on the UTM transformers.
I was doing a list with the UTM parts and equivalence to other known transformers so that I know what is available and I can choose that depending on the project.
This is the list I was able to do with the help of IGS also:
UTM3580 = Sowter 9745
Best Regards
thanks for joining this thread, it's great to be able to have more info on the UTM transformers.
I was doing a list with the UTM parts and equivalence to other known transformers so that I know what is available and I can choose that depending on the project.
This is the list I was able to do with the help of IGS also:
| MIC input | Equivalent | |
| UTM2545 | Carnhil VTB9045 | Neve L10468 |
| UTM2546 | Carnhil VTB9046 | Neve L31267 |
| Line input | ||
| UTM2571 | Carnhil VTB9071 | |
| Line Level Out | ||
| UTM3502 | UA-5002 | 1176, rev A-D circuit |
| UTM3504 | UA-5002 | 1176, rev A-D circuit low-profile for 500 series (EI-41 core) |
| UTM2510 | Teletronix LA2A and UA175 | UTC A-10 replacement |
| UTM3523 | API 2623 output | 75:300 |
| UTM3503 | API 2503 output | 300:300 |
| UMT3507 | B11148 | 1176 - Rev E-H e Gyraf |
| UTM3505 | B11148 | 1176 - Rev E-H e Gyraf |
| UTM3515 | LA2A or REDD output transforme | |
| UTM3501 | Recommended for any kind of API-ish style output amplifiers | |
| UTM3556 | Carnhill VTB9056 direct replacement | |
| UTM3580 | Altec 436 and many other vari-mu, push-pull circuits | |
| UTM3547 | Carnhill VTB1148 (PCB mounted, 8 wires) | LO1166 |
| UTM3548 | Carnhill VTB1148 (clamped, 4 wires) | LO1166 |
| UTM3501 | Edcor PCW, 1/2W, 600Ω to 150Ω, low profile, for 500-series modules | |
| UTM2555 | VTB9045 but 1:7 ratio | |
| UTM2571 | Carnhill VTB9071 | |
| UTM2581 | Carnhill VTB2381 | |
| UTM2582 | Similar to Carnhill VTB2381 but 1:7 stepup possible | |
| UTM1543 | Carnhill VTB9043 | |
| UTM1544 | Carnhill VTB9044 | |
| UTM1550 | Carnhill VTB9050 |
Best Regards
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Thanks for the clear table. It's a good idea.
UTM3547 - Carnhill VTB1148 (PCB mounted, 8 wires),
UTM3548 - Carnhill VTB1148 (clamped, 4 wires),
UTM3501 - Edcor PCW, 1/2W, 600Ω to 150Ω, low profile, for 500-series modules,
UTM2545 - Carnhill VTB9045,
UTM2546 - Carnhill VTB9046,
UTM2555 - Similar to VTB9045, stepup 1:7,
UTM2571 - Carnhill VTB9071,
UTM2581 - Carnhill VTB2381 (not listed on the Carnhill's Design Guide - Issue 1e),
UTM2582 - Similar to Carnhill VTB2381 but 1:7 stepup possible.
UTM3504 and UTM3505 are low-profile, suitable 500-series modules transformers, (30mm high) dedicated for 1176 DIY modules. The parameters are slightly different, coz the core is smaller (EI-41).
You can update your table and I'll delete this post to keep this thread clear now.
UTM3547 - Carnhill VTB1148 (PCB mounted, 8 wires),
UTM3548 - Carnhill VTB1148 (clamped, 4 wires),
UTM3501 - Edcor PCW, 1/2W, 600Ω to 150Ω, low profile, for 500-series modules,
UTM2545 - Carnhill VTB9045,
UTM2546 - Carnhill VTB9046,
UTM2555 - Similar to VTB9045, stepup 1:7,
UTM2571 - Carnhill VTB9071,
UTM2581 - Carnhill VTB2381 (not listed on the Carnhill's Design Guide - Issue 1e),
UTM2582 - Similar to Carnhill VTB2381 but 1:7 stepup possible.
UTM3504 and UTM3505 are low-profile, suitable 500-series modules transformers, (30mm high) dedicated for 1176 DIY modules. The parameters are slightly different, coz the core is smaller (EI-41).
You can update your table and I'll delete this post to keep this thread clear now.
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Do you know that adding a frame to a xfmr slightly increases the inductance? Just because the lams are more compressed. Not huge difference , about a few %.
I didn't know that, thanks you so much for the info.
But the core is smaller also (EI-41) in this case like igs said, so it makes sense now.
Thank you both
TwentyTrees
Well-known member
That's definitely worth knowing, thanks! Have been removing the frames from a load of Jensen quadfilar outputs recently without even thinking about it, I'll try measuring L before and after next time.
Anyway, back on topic it's great to see a new EU source for iron and hats off to UTM and IGS for opening their wares up to the DIY crew. Wonder if there's anything in the catalogue similar to a UTC A-25, that would do for an RCA BA-2C preamp output... (9:1, gapped for 5 or so mA DC).
Hi igd,
I forgot the UTM2555 mic input tx in the list...
Whats that one?
Thank you
I forgot the UTM2555 mic input tx in the list...
Whats that one?
Thank you
For transformers, it doesn't really make a difference, but for filters it does, shifts frequency by a few %.
ruffrecords
Well-known member
Whether that is enough turns depends on the permeance of the core material. Do you have an Al figure for it?
To put this into context, inductance = Al x N x N so Al = inductance / (N x N). With primaries in series you have 2500 turns and a measured inductance of 19H which means Al is about 3uH/turn^2.
So if you doubles the turns to 2500 per winding for a total of 5000, the inductance would increase to 75H which at 20Hz has an impedance of about 10k ohms.
Cheers
Ian
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