hi everyone,
I'd like to build a simple clone of the AMPEG SVT-DI box.
it's pretty simple, for the output transformer I'm going to use a Jensen JT-DB-E (should be right for this job I guess).
I just need to find a power transfomer.
Do you have any suggestion about a particular (I prefer cheap :icon_razz:) transformer that I could use?
thanks
(https://i.postimg.cc/WdMsJhW7/SVTDI_schematic.jpg) (https://postimg.cc/WdMsJhW7)
This should do the job nicely. https://www.tedweber.com/wpdlpt (https://www.tedweber.com/wpdlpt)
Thank you! Looks pretty cool but unfortunately I'm in Italy and Weber has got some pricey shipping options to Europe, this would cost me about 100$
Quote from: Dimitree on October 05, 2018, 10:12:38 AM
Thank you! Looks pretty cool but unfortunately I'm in Italy and Weber has got some pricey shipping options to Europe, this would cost me about 100$
Scroll down to the bottom of this page and check out the low power transformers here https://hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=Transformers&ORDER_ID=792456230 (https://hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=Transformers&ORDER_ID=792456230) they're the same ones as EHX tube stuff.
Quote from: wavley on October 05, 2018, 10:24:04 AM
Quote from: Dimitree on October 05, 2018, 10:12:38 AM
Thank you! Looks pretty cool but unfortunately I'm in Italy and Weber has got some pricey shipping options to Europe, this would cost me about 100$
Scroll down to the bottom of this page and check out the low power transformers here https://hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=Transformers&ORDER_ID=792456230 (https://hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=Transformers&ORDER_ID=792456230) they're the same ones as EHX tube stuff.
that one looks great, but is it safe to use it in reverse like that?
I've seen people using two of them, like this: 220V -> 12V -> 12V -> 220V
would that be wiser?
Quote from: Dimitree on October 05, 2018, 11:15:15 AM
Quote from: wavley on October 05, 2018, 10:24:04 AM
Quote from: Dimitree on October 05, 2018, 10:12:38 AM
Thank you! Looks pretty cool but unfortunately I'm in Italy and Weber has got some pricey shipping options to Europe, this would cost me about 100$
Scroll down to the bottom of this page and check out the low power transformers here https://hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=Transformers&ORDER_ID=792456230 (https://hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=Transformers&ORDER_ID=792456230) they're the same ones as EHX tube stuff.
that one looks great, but is it safe to use it in reverse like that?
I've seen people using two of them, like this: 220V -> 12V -> 12V -> 220V
would that be wiser?
That's the way all of the EHX tube pedals are and I haven't seen any problems in the two I own. You use the flatpack transformer with a wall wart that puts out 12VAC, pull the heaters off of the wall wart in parallel with the input of the flat pack so that way you get a heater and an HT out of two transformers, the wall wart providing any isolation from the wall you need.
The drawing shows a DC heater supply. Once you rectify the 50/60 Hz input, you generate harmonics that extend into the audio range. The fundamental will be below the flat part of the bandpass and it should not be too much of a problem to go without rectification and filtering. The best thing to do with the heater voltage is to raise it to a positive level above ground. That way, any emission from the heater itself will be stopped by the grid post which will be approximately at ground.