Mono bloc vs separate PSU?

[Lokidtc99]

Evening all.

I'm thinking about building another HackerNAP to bi-amp my speakers, and wondering what the point of diminishing returns is wrt separation of components into separate boxes.

So, is it safe to assume that the following represents a series of options in ascending order of improvement?

0) [Single transformer, L&R HackerCAPs, L&R HackerNAPs]
1) [Single transformer, with L & R HackerCAPs] --> [L & R HackerNAPs]
2) [Single transformer, with L & R HackerCAPs] --> [L HackerNAP] & [R HackerNAP]
3) [L transformer & HackerCAP] & [R transformer & HackerCAP] --> [L HackerNAP] & [R HackerNAP]

And if so, how would you rank the gains in each step?

 

[Mynamemynaim]

You missed out
Tx in its own box feeding HackerCap (in its own box) into HackerNap in its own box
All times two
The ultimate 6 box amplifier!!

Seriously...its very difficult to say where it all stops being a slight improvement and turns into a total mass of box's and wires...

Just build the best you can (I agree with your list roughly) and spend the other money on improving your sources

Personally...I built duel monos with two transformers in each box....but with "cages" built round each Tx to keep noise and Interference to a minimum in my latest amp....seems to work well

 

[Richard Lines]

@Lokidtc99 - In all honesty if your toroid is big enough i.e. in VA terms you can put everything in one box powered off that one transformer.

My stereo NCC200 'Voyager' is driven by a 818VA 'beast' of a toroid and I have a stereo NCC300 'Voyager' driven with 2off 500VA and I have another stereo amplifier with twin 340VA transformers.

There is no sign of hum or interference in any of the amplifiers. I've no doubt many on here might argue that a 500VA transformer for one channel is 'overkill' let alone 340VA.

I don't believe there is any significant sonic benefit in building mono's they are just easier to move around. One larger (ModuShop) case will also be cheaper than two smaller ones?

Regards

Richard

 

[martin clark]

You missed out
Tx in its own box feeding HackerCap (in its own box) into ...

I know it was suggested in jest, but never separate the transformer from rectifier from reservoir caps.
The heavy, peaky current flow in the larger loops radiates a lot of noise and will very efficiently couple into the rest of the system.
Keep the layout and wiring tight for raw PSUs , always.

 

[Avon]

never separate the transformer from rectifier from reservoir caps.

That’s an interesting point, Martin. I apologise for drifting off topic somewhat, but I have two low-powered devices with AC wall warts, with rectification and smoothing inside the device itself (a Schitt Eitr and a Rega Fono). Presumably these can get away with it, given the low currents involved?

 

[martin clark]

Yes; the other aspect is that small AC transformers have significant primary and secondary resistances , and this is a useful quality in that it provides useful damping / keeps the peak currents down - the charging pulses of longer duration, but much lower peak current than would be the case with a 'bigger'/ low-impedance transformer. This somewhat mitigates the EMC issues with such a simple arrangement.

 

[a.palfreyman]

Keep the layout and wiring tight for raw PSUs , always.

Most definitely. In my experiments, just taking the amplifier front end earth return to the psu via a different route to the power wires / load earth return (twisted together) was sufficient to add a mV or 2 rectifier noise pick-up to the output. Bundling the front end earth return in with the others cured it.