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  • Transformer Suppliers in the UK / EU

    I'm having a hard time sourcing a PT and OT for Marshall JTM45/50 based builds. PT to support a GZ34, HT winding 350-320-0-320-350, laydown mounting, bolts on a 3.75" x 3" spacing for a premade aluminium chassis. OT to have 6k6 primary to 8 and 16 secondary.
    Any recommendations? I'm in contact with Piemme Ekektra but he can't quite manage the PT mounting spacing. Also aware of inMADout and Savino Luce. Thanks!
    My band:- http://www.youtube.com/user/RedwingBand

  • #2
    Did you check TAD?
    - Own Opinions Only -

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    • #3
      Originally posted by Helmholtz View Post
      Did you check TAD?
      Yes thanks, and Tube Town. Sorry, I should have mentioned that. The tapped options for the HT winding are the problem with both of these. I want an option for solid state rectification, and want to avoid an excessive HT / redplating power tubes, so lower voltages taps would be helpful with that
      I wish Ingo Gorges was still in business
      Last edited by pdf64; 11-10-2020, 06:41 PM.
      My band:- http://www.youtube.com/user/RedwingBand

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      • #4
        Originally posted by pdf64 View Post
        I wish Ingo Gorges was still in business
        Yes, Ingos transformers were excellent. Comparable to Merren/Cerrem transformers in the US: http://www.merrenaudio.com/marshall_power_transformers

        - Own Opinions Only -

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        • #5
          I've used these, very happy with results:

          http://www.demeterwindings.co.uk/home.html

          http://www.trans-tronic.co.uk/ - They also started their own range of valve transformers but I can't seem to find the site.

          Aware of these, others have recommend them but never used:

          http://primarywindings.com/design-service/

          http://www.transformerequipment.co.uk/contact/index.htm

          https://www.transformers.uk.com/ (Majestic as used by Cornell)
          Experience is something you get, just after you really needed it.

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          • #6
            I have been using Luke at http://www.transformerequipment.co.uk/contact/index.htm for about 8 years rewinds and replacement tx, always found them good never had an issue and price is good too,

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            • #7
              http://www.inmadout.com/
              https://www.welter-electronic.de/inf...ndenbilder.htm
              http://www.tubesoundelectronics.de/
              https://www.roehrentechnik.de/html/ausgangstrafos.html
              https://www.tbtroehrentrafo.com/
              https://www.weiss-trafo.de/
              ......
              Last edited by catalin gramada; 11-14-2020, 01:16 AM.
              "If it measures good and sounds bad, it is bad. If it measures bad and sounds good, you are measuring the wrong things."

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              • #8
                Originally posted by pdf64 View Post
                I'm having a hard time sourcing a PT and OT for Marshall JTM45/50 based builds. PT to support a GZ34, HT winding 350-320-0-320-350, laydown mounting, bolts on a 3.75" x 3" spacing for a premade aluminium chassis. OT to have 6k6 primary to 8 and 16 secondary.
                Any recommendations? I'm in contact with Piemme Ekektra but he can't quite manage the PT mounting spacing. Also aware of inMADout and Savino Luce. Thanks!
                I have worked with Savino about a dozen times already, several of those times for custom spec'ed trannies that included 5v taps as well as a lowered PT secondary voltages. Easy to work with, great price, and having several different brands of trannies I'd put him in the top tier. The "presentation" could leave a bit to be desired, but otherwise I can not complain.

                You being in the UK, ever think of Sowter? I am always looking for new tranny companies to try... I have read a few good things about Sowter in the past, but they are expensive also.... Mercury expensive.

                FWIW, my next purchase will more than likely be via Marstran in the US. The shipping etc will likely cost an arm and a small leg (150 euros'ish), but his trannys are also Heyboer produced (as is Metro amp in the US, my most recent purchase for a JTM45 build). But, I know... you said UK/EU :-) Sometimes you have to reach into the bowels of hell to get what you want.
                Last edited by Gtr0; 11-14-2020, 07:56 AM.
                "'He who first proclaims to have golden ears is the only one in the argument who can truly have golden ears.' The opponent, therefore, must, by the rules, have tin ears, since there can only be one golden-eared person per argument." - Randall Aiken

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                • #9
                  I just checked the inMADout site. Nice range of types. But no price info.

                  Interestingly they spec input and output power with OTs.

                  From this data I calculate an efficiency of 80% for their RadioSpares type.
                  Means that only 32W of 40W will be transferred to speaker, while the 8W difference heats the OT.
                  That's really low efficiency for an OT.

                  Their 50W Plexi type, OTOH, is specced with an efficiency of 94%, resulting in only 2.5W losses with 40W input.
                  - Own Opinions Only -

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                  • #10
                    Originally posted by Gtr0 View Post

                    I have worked with Savino about a dozen times already, several of those times for custom spec'ed trannies that included 5v taps as well as a lowered PT secondary voltages. Easy to work with, great price, and having several different brands of trannies I'd put him in the top tier. The "presentation" could leave a bit to be desired, but otherwise I can not complain.

                    You being in the UK, ever think of Sowter? I am always looking for new tranny companies to try... I have read a few good things about Sowter in the past, but they are expensive also.... Mercury expensive....
                    Thanks for reporting your good experience of working with Savino.
                    I'm communicating with Transtronic and Transformer Equipment guys at the moment, hopefully one of those will work out if I don't drive them nuts first
                    If not, I'll try Savino.

                    I've used Sowter back in the 80s and 90s for regular and custom guitar amp iron. They used to advertise in Wireless World etc, and it wasn't easy to find anyone else for 1 offs. They were really helpful and their stuff is great; back then their pricing was high but reasonable, whereas it's gone crazy high since the 2000s, seemingly higher even than Mercury

                    Originally posted by Helmholtz View Post
                    I just checked the inMADout site. Nice range of types. But no price info.

                    Interestingly they spec input and output power with OTs.

                    From this data I calculate an efficiency of 80% for their RadioSpares type.
                    Means that only 32W of 40W will be transferred to speaker, while the 8W difference heats the OT.
                    That's really low efficiency for an OT...
                    Is it feasible that a properly made OT could be that inefficient? I'm wondering if somehow a mistake, eg in the data or how they describe it, seems more likely
                    My band:- http://www.youtube.com/user/RedwingBand

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                    • #11
                      Originally posted by pdf64 View Post
                      Is it feasible that a properly made OT could be that inefficient?
                      Power loss of 20% actually seems extremely high in a PP OT. I would expect an RS type to have more losses than a standard 50W Marshall OT, because the core and coil former are a bit smaller and the multiple windings will force the use of thinner wire, so that copper and core losses will be somewhat higher. But hardly a factor of 8, maybe a factor of 2.

                      OTOH, the values for the "50W" Plexi type look a bit too optimistic.
                      A typical 50W Marshall OT has a DCR of around 50R per primary side and reflected impedance per tube is 800R. So it's efficiency must be be less than 94% as there are also secondary and core losses (increasing with frequency).

                      I once measured efficiencies of a number of PTs (when I had access to 2 lab grade power meters). Efficiencies better than 92% I only found with larger toroidal types.
                      OTs can be expected to be somewhat more efficient than PTs as they are typicall larger than PTs of same wattage and don't run as hot.
                      PTs are often designed for equal copper and core losses at full power.
                      Last edited by Helmholtz; 11-16-2020, 08:35 PM.
                      - Own Opinions Only -

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                      • #12
                        A bit of resurrection...

                        Originally posted by pdf64 View Post
                        I'm having a hard time sourcing a PT and OT for Marshall JTM45/50 based builds. PT to support a GZ34, HT winding 350-320-0-320-350, laydown mounting, bolts on a 3.75" x 3" spacing for a premade aluminium chassis. OT to have 6k6 primary to 8 and 16 secondary.
                        Any recommendations? I'm in contact with Piemme Ekektra but he can't quite manage the PT mounting spacing. Also aware of inMADout and Savino Luce. Thanks!
                        So who did you end up going with? I want to build an authentic'ish Marshall 50 watt... using old Philips and Phier components, everything else will be modern production. Normally I would jump at the change for Marstran or Metro Amp trannys (both are Heyboer), but the shipping and taxes on my last set were over $200 (coming to Belgium). I am not rolling in the extra dough at the moment, but I could hold out for a set from Marstran or Metro if I can find nothing comparable. I would like to avoid dagnall modern production. I have a 100 w build with them and it sounds just like my 1959SLP reissue... like it has some horrible sounding limiter (with a hint of paper tearing) on the low end. On my 1959slp, I swapped the OT for a Hammond and that issue was greatly alleviated. It's a mystery to me to be honest. But my taste for modern Dagnall's has been forever sullied.

                        Also I have a few builds with Inoutmad... so I wouldn't mind a switch, though one of my favorite sounding amp is using those. Just feel like trying something different that retains a super high build quality... if possible.

                        "'He who first proclaims to have golden ears is the only one in the argument who can truly have golden ears.' The opponent, therefore, must, by the rules, have tin ears, since there can only be one golden-eared person per argument." - Randall Aiken

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                        • #13
                          BTW, does anyone know if tube town trannys are made by Inoutmad?
                          "'He who first proclaims to have golden ears is the only one in the argument who can truly have golden ears.' The opponent, therefore, must, by the rules, have tin ears, since there can only be one golden-eared person per argument." - Randall Aiken

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                          • #14
                            I was hoping to have reported back with glorious sound clips of the resulting amp well before now. But it’s still a work in progress with, at the current sluggardly work rate, there's still a few weeks to go.
                            And no one to blame but myself, I had the transformers, from Luke at Transformer Equipment, before Christmas.

                            A 6k OT and RS type choke from him have gone into my JTM45ish build, which sounds great, and I consider an them upgrade from the RS Deluxe OT and 8k 784-103 clone by Ingo Gorges units that were in there previously fitted.

                            I had a good response and quote from trans-tronic, but they were a lot more expensive.
                            With them and Luke, it was a bit of a struggle getting them to design it vintage style, with plenty of winding resistance.

                            Majestic Transformers responded eventually, I got the impression they were in pandemic mode at the time.
                            I'd also been corresponding with Maurizio at Piemme Ekektra in Italy, but his laminations have different footprints to vintage types, and I was getting a chassis with a cut out for a laydown vintage sized PT.

                            I had a similar thread over on TAG https://ampgarage.com/forum/viewtopi...418746#p418746
                            My band:- http://www.youtube.com/user/RedwingBand

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                            • #15
                              Originally posted by pdf64 View Post
                              I'm wondering about your statement from the other thread/forum:

                              >It's worth noting that with the RS Deluxe, the reflected load changes from about 6k4 with a 16ohm load and the secondaries wired for 16ohms, to about 5k5 with a 8ohm load and the secondaries wiried accordingly.<

                              Is this based on impedance measurements on an original RS Deluxe?



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