The transformer
Toroidal transformers for all
Studer Revox B250, B250 S, B250 E
Why do Revox transformers tend to hum?Well, many amplifiers from other manufacturers don't even get old enough for the transformers to start humming!The first Revox B250 amplifiers are now over 40 years old. It took us a long time to find an internal solution for replacing the humming transformer. Only after replacing the power supply board did we have enough space to install a powerful toroidal transformer. The new premium hi-fi transformer has a power output of 520 VA. That's more than sufficient for the Revox amplifier. We don't have a single millimeter of space between the housing, the transformer, and the power amplifier's heat sink—we can't get any more!Thanks to our solution with the mounting plate and the new power supply board, no modifications are required to the Revox B250 amplifier. No additional holes need to be drilled. Everything fits perfectly!
Revox's external solution in a hammer-finished housing is just rubbish.
A small auxiliary transformer keeps the Revox B250's standby circuit running (not necessary for us!). The amplifier has an additional hole for the cable feedthrough (not necessary for us!).The external transformer is only half-used, with only one winding connected. This is a tragedy, to say the least! Our transformer is custom-made for this application; there's no leftover stock.
Installation in Revox B150, B250 /E /S
Trafo in B250
We were once asked how much power the Revox B250 amplifier has with the new transformer.
Look at the picture: you can't fit more than 520 VA into the transformer! No matter how high the power is, you can't get any more!
But rest assured - there is more than enough power and plenty of reserve too!
construction
Thanks to many small design features, we were able to install the new transformer without any modifications to the Revox B250 integrated amplifier (no additional holes or other work). Theoretically, it's possible to reinstall the old transformer – and you won't notice anything!
connectors
Of course you will receive the appropriate connectors!
Except for the two 230 V AC wires, everything is pluggable. If we had been able to get the right power sockets, installation would have been possible without any soldering. Please also be aware of the dangers of mains voltage; please observe the regulations for Protection Class II.
New power supply board
Thanks in no small part to the new power supply circuit board, we were able to offer an internal transformer solution with ample power. The circuit board contains all the components of the old power supply board plus the five secondary fuses!
Old and new
After many inquiries and considerable consideration, we came up with the idea of replacing the original power supply circuit board with a new one. The electrolytic capacitors were also given bypasses and the voltages were adjusted to meet our needs. No 24 V relay should be operated at 32 V. Check it out!
Revox B250 S
Everything's perfect! The installation, the sound, less power loss, less heat generation!
If other competitors try to discredit you with some kind of pseudo-leakage current from their electrolytic capacitors, we have the perfect internal solution for you. Ultimately, it's all about preserving the value and longevity of Revox devices!
Transformers in our shop
Here you will find toroidal transformers for Studer and Revox devices.
