I am not sure if you're intending on also doing dual mono ie 4 transformers or just stereo with separate transformers for each rail ie 2 transformers
If it is going to be a stereo setup with 2 transformers, I think you would get far greater value from 2 transformers going with dual mono setup.
If it is going to be a stereo setup with 2 transformers, I think you would get far greater value from 2 transformers going with dual mono setup.
Sorry, I should have more clearly stated that I have two monoblocks already, each with its own external power supply. I have a second ps in each chassis so that I can run four total channels if desired, but haven't been using that capacity. Once I decided not to run the extra channels (for biamping) I just pulled the fuse from the standard store power supply in each chassis... hence the extra, unused transformer.
If you want to use one transformer for each supply rail you will not get the full 400va rating if you do not parallel the windings.
Cal
Honestly not sure whether there is a lot to gain with 2 transformer per monoblock/1 per voltage rail setup you described, however there is a risk to call out
In case one of your transformers, or connection to your transfromets fail, you might have substantial DC in the output
Your speakers might not like it 😉
Honestly not sure whether there is a lot to gain with 2 transformer per monoblock/1 per voltage rail setup you described, however there is a risk to call out
In case one of your transformers, or connection to your transfromets fail, you might have substantial DC in the output
Your speakers might not like it 😉
Thanks for the warning, I appreciate it. If I don't hear much change in sound, I'll definitely go back to a single.
I think it's usually done when a transformer larger than 1kVA is required and 2 smaller transformers fit into the chassis easier than one huge monster.
I don't think it will really ad much improvement especially with a CRC supply connected. The amp is mostly seeing the output caps because of the resistors in between. There could be some improvement but not sure whether it will be that significant or even audible.
I don't think it will really ad much improvement especially with a CRC supply connected. The amp is mostly seeing the output caps because of the resistors in between. There could be some improvement but not sure whether it will be that significant or even audible.
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Given that I have the parts just sitting there already loaded in the two PS chasses, any improvement at all is worth it as long as I'm not making any tradeoffs. The DC issue is real though. I actually already did the rewiring this morning because of tech issues at work that made my laptop unusable. I'll get back in there this afternoon and put both trannies on the same fuse to minimize the DC risk. Won't be able to listen until tonight...
I like it. Definitely a small effect, but I do think the rail ps independence removed a bit of distortion. Feeling a touch more relaxed.
Perhaps I've just picked the right albums tonight, but I'm growing more and more enamoured with this change. I think if you've committed to a long term relationship with the f4 like I have, it's a worthwhile addition to the design. Loving everything I've heard all night...
Could be just due to effectively doubling your transformer VA rating per channel.
Great to see you're getting enjoyment from the mod.
Great to see you're getting enjoyment from the mod.
Agreed, totally possible. They are 400V transformers though, so I was starting at maybe double the standard stereo design value already. 1600V total is pretty ridiculous for a little 25W/channel amp...
^This is my situation. Although I was only considering 800VA
^This makes me re-think some things.
^Agreed.
For balanced BA-3 monoblocks, I had planned on using 1 entire PSU per phase. Similar to Cal3713, I have everything already. 2x Dual mono BA-3s to be converted to a pair of balanced monoblocks. I haven't decided whether I will have balanced to SE be 'user switchable' on the BA-3 front end similar to some builds I've seen.
A difference is that I have 4 identical supplies from donuts through filtering. Is it wiser to use a donut per rail? In "balanced / mono mode" if I lose a donut, either one rail dies or one phase dies. In "SE / stereo mode" it seems that losing one channel is a better scenario than losing a rail to both channels. I could be missing other considerations.
I'm wondering If I should rethink the whole thing. If I move forward, DC protection is a much bigger consideration now.
Not very high IME. In 40 years of working with electronics I have seen few transformer failures. If properly designed and operated within their design specs, transformers are easily capable of running for 50 years trouble free.
The other parts of your power supply are much more likely to fail first.
My recommendation is to include speaker protection in your amplifiers. Unless you have DIY speakers and you know you can get replacement woofers at a cost you can afford, it is cheap insurance to include a protection circuit.
The other parts of your power supply are much more likely to fail first.
My recommendation is to include speaker protection in your amplifiers. Unless you have DIY speakers and you know you can get replacement woofers at a cost you can afford, it is cheap insurance to include a protection circuit.
How are the two transformers fused? If they are fused separately what happens
if one blows and the other doesn't?
if one blows and the other doesn't?