Hello,
I am needing a few transformers for an audio pre-amp I am building. The specified transformers for the schematic (Transcendent Sound Grounded Grid) are two 120V 50mA transformers (one for the B+ & and the other for the B- circuits), as well as two 12V 1A transformers for the Filament circuit and volume/input relay boards. I could also use one 12V 2A transformer in place of the two separate 12V 1A transformers. I am very new to transformers and do not want to pick the wrong transformers. Can you please help me locate the transformers that I need? I am looking for high quality transformers, but do not have unlimited funds to spend, if that helps.
http://www.plitron.com/shopping/sho...id=3&cat=Standard+Power+Toroidal+Transformers
I have pasted a link to the Plitron website's standard power toroidal transformers page.
Thanks for any and all help! I have the GG schematic, but it is too big to post in this thread. I can email to anyone if they need to see it.
Dan
I am needing a few transformers for an audio pre-amp I am building. The specified transformers for the schematic (Transcendent Sound Grounded Grid) are two 120V 50mA transformers (one for the B+ & and the other for the B- circuits), as well as two 12V 1A transformers for the Filament circuit and volume/input relay boards. I could also use one 12V 2A transformer in place of the two separate 12V 1A transformers. I am very new to transformers and do not want to pick the wrong transformers. Can you please help me locate the transformers that I need? I am looking for high quality transformers, but do not have unlimited funds to spend, if that helps.
http://www.plitron.com/shopping/sho...id=3&cat=Standard+Power+Toroidal+Transformers
I have pasted a link to the Plitron website's standard power toroidal transformers page.
Thanks for any and all help! I have the GG schematic, but it is too big to post in this thread. I can email to anyone if they need to see it.
Dan
Why don't you choose candidate transformers and someone will comment on your choice? Less work for us = more responses.
Have you got a link to the schematic?
Have you got a link to the schematic?
I found a guy who is going to custom wind these transformers for me into one toroidal. Is it going to either help or hurt the sound to combine the two 12V transformers into a 2A version or is it better to keep two separate 12V 1A transfomers for the filament and volume control/input relay boards?
Thanks again,
Dan
Thanks again,
Dan
multiple windings on a common core will be a much bigger help in keeping noise out of clean circuits.
But better still are separate transformers.
Keep the noisy stuff separate from the clean.
But better still are separate transformers.
Keep the noisy stuff separate from the clean.
Would it be better to get separate EI transformers instead of the toroidal one? I have found EI transformers that will work that are about the same price as the one toroidal one. It's $42 for the custom wound toroidal and $26-$28 per single toroidal transformer. Would it just be better to get separate ones? I have the space for them. As for the 12V transformers, so it would be better to keep them separated as 1A transformers?
Thanks again for your help,
Dan
Thanks again for your help,
Dan
Hi,
you mentioned relays, what other noisy souces have you got? fan, smps?
If you have these then separate transformers are probably better,
EI are usually heavier and bulkier, but cheaper.
Your 1Aac can source upto 500mA DC after rectification and smoothing. Is this enough? most would tend to run a transformer continuously at no more than 50%. That brings you down to 250mAdc continuous.
you mentioned relays, what other noisy souces have you got? fan, smps?
If you have these then separate transformers are probably better,
EI are usually heavier and bulkier, but cheaper.
Your 1Aac can source upto 500mA DC after rectification and smoothing. Is this enough? most would tend to run a transformer continuously at no more than 50%. That brings you down to 250mAdc continuous.
No fans or anything. The relay is actually just a input board/volume control. It is speced to be powered by a 12V 1A transformer. The filament supply is speced to be powered by a 12V 1A transformer as well. Bruce B., owner and designer of Transcendent Sound products, said that the transformer only uses about a 1/2A, but the volume control uses up to the full 1A, which is why I need two transformers, or I can replace the voltage regulator to a 2A and use a 12V 2A transformer, which Bruce said would work. I am building a Transcendent Sound Grounded Grid Pre-amp.
Does that help?
Dan
Does that help?
Dan
It appears from your description that all the audio is supplied by the 120V transformer and that the low voltage transformer is only supplying the relays.
Where does the valve heater supply come from?
If there is a separate tapping for the heater on the 120V transformer, then I suggest a 24VA to 50VA 12Vac transformer for the relays.
A transformer/rectifier PSU can easily meet a short term demand well in excess of what it can do continuously, so the short term 1A is not a problem. But, if the 1A can become continuous due to all the relays holding in simultaneously then go for the higher VA.
Where does the valve heater supply come from?
If there is a separate tapping for the heater on the 120V transformer, then I suggest a 24VA to 50VA 12Vac transformer for the relays.
A transformer/rectifier PSU can easily meet a short term demand well in excess of what it can do continuously, so the short term 1A is not a problem. But, if the 1A can become continuous due to all the relays holding in simultaneously then go for the higher VA.
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