Pre & Power

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Daniel Quinn
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Re: Pre & Power

Unread post by Daniel Quinn »

Read the interview with the doc, he hated capacitors

29mile
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Re: Pre & Power

Unread post by 29mile »

See Richard's post from DIY amplifier build below which I think confirms Tomasz's view :

Re: Another DIY SS Amplifier with NVA Boards
Post by Dr Bunsen Honeydew » Thu Apr 05, 2018 6:44 pm

For me a production cost increase of £20 for the benefit was not justified. I only tried the DNM split films way back.

Cheaper main caps and using bypasses was more cost effective.

I am 90% sure these caps were fitted originally on the A60 given the way they have been mounted. There was no space just after the main smoothing caps to fit them so I think they were fitted above the boards instead.

Daniel Quinn
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Re: Pre & Power

Unread post by Daniel Quinn »

That is specific comments on necessary caps, I fail to see how it supports Thomasz view. Again read the philophical discussion about caps in the interview.

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Re: Pre & Power

Unread post by Daniel Quinn »

On the nva amp boards there are only 3 caps, all 100uf or less. That is the least you'll find except for quad 405.

Vinyl-ant
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Re: Pre & Power

Unread post by Vinyl-ant »

Nelson pass f5 has no caps in the circuit other than the psu caps. It's a very simple circuit to look at, but as usual it's not so simple as it looks.
Some valve amp circuits can get away with none such as a drd type topology, some se designs can have as few as 3, cathode bypass caps on the input and output valves and a coupling cap between stages. If there is enough gain, it's possible to do it with one coupling cap. Wether you would want to is another matter.
There are probably other examples
Analogue: oracle delphi sme 309, jbe series 3 cx unipivot dv20x2l, roksan xerxes tabriz vm750, jvc ql-y5f rigb at440, jvc ql-y3f vm750, lenco 75, technics sl150

Phono stages: cole lcr, benedict audio hothead

Digital: cyrus cd7, wiim mini x2, topping e30, jds labs el dac 2+

Amplification: nelson pass b1, nelson pass f5

Speakers: 15" fane aperiodic wardrobes

Cans: myryad z40, hifiman sundara + deva, fostex t50rp, sennheiser momentum on ear +over ear, b&w p5 and p7

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Re: Pre & Power

Unread post by Daniel Quinn »

Valve, no. Nelson pass hmmmm. Can you purchase the boards.

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Re: Pre & Power

Unread post by Vinyl-ant »

Yes I believe they are still being made via DIY audio. there are 2 available I think, the standard nominally 25w version and a 'turbo' version with more power. You can also get the psu cap boards for them

There are a couple of other pass boards available, the aleph j and I think the band camp board, I dont know what the circuit is with those boards though and I haven't heard them
Analogue: oracle delphi sme 309, jbe series 3 cx unipivot dv20x2l, roksan xerxes tabriz vm750, jvc ql-y5f rigb at440, jvc ql-y3f vm750, lenco 75, technics sl150

Phono stages: cole lcr, benedict audio hothead

Digital: cyrus cd7, wiim mini x2, topping e30, jds labs el dac 2+

Amplification: nelson pass b1, nelson pass f5

Speakers: 15" fane aperiodic wardrobes

Cans: myryad z40, hifiman sundara + deva, fostex t50rp, sennheiser momentum on ear +over ear, b&w p5 and p7

Daniel Quinn
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Re: Pre & Power

Unread post by Daniel Quinn »

Thanks, I'll take a look

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Re: Pre & Power

Unread post by savvypaul »

Daniel Quinn wrote: Mon Mar 09, 2020 11:57 am Read the interview with the doc, he hated capacitors
Tomasz interviewed Richard 5 days a week for the best part of 3 years...
I am in the hi-fi trade
Status: Manufacturer
Company Name: NVA Hi-Fi
https://nvahifi.co.uk/

Daniel Quinn
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Re: Pre & Power

Unread post by Daniel Quinn »

Richard never indicated he change is view. In fact he was always referring to that interview.

however there may be a language issue here. Richard said the only good component was no component. So he hated them all. But you have to use them to design. The fact remains he used a circuit with very few in, because he was aware they fucked up the sound.

Furthermore Richard was talking about power supply caps, when he offered the advise reffered to, by thomasz. You have to use power supply caps.

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