[joad004]

Hi,

Sorry for writing in english, eventhough I can read and understand german quite good you would have a hard time understanding my written german.

I am building my second tube amp (SLO50W with modified preamp) and  since I have looked at the JCM800 type torodial PT at tubetown I am thinking about using that one.  However, there seems to be some users reporting that you will have issues using a Torodial PT. For example at ax84.com there has been reports about more issues with hum..

Have any of builders used a torodial PT in your builds? If so, did it work out ok?

Cheers from Sweden,
Johan

[Dirk]

Hallo,

normaly you should have less hum problems with torodial transformers than with normal EI PTs. I prefer the torodial even if they do not look so good as the "old" PTs.

Best regards, Dirk

[joad004]

Hi Dirk,

Less hum sounds good since I have an idea of trying out a rack type amp this time. Thanks for replying.

Cheers,
Johan

[Pharos]

Hi Johan,
I second that, toroidals usually produce a lot less hum than EI transformers. The only "drawback" is a higher surge current due to the low leakage inductance - but this should not cause problems.

PS: "totoidal vs. Iron based" is definitely misleading, since toroidals are also made from iron. It is usually one long rolled up strip of iron.

[joad004]

Hi Pharos,

Does this surge current put more stress on capacitors, switches or will it also affect B+ voltage during load?

I know that my title was a bit misleading but I could find a good word for EI type transformers except that you see more iron on them :-)

Thanks,
Johan