Passive pre-stage / power amp / speakers.

[Wil]

Be careful with these speakers and some Class-D amps:

View attachment 522550
High frequency impedance goes towards zero meaning this is a highly capacitive load. Some Class D amps don’t particularly like this. It would be good to check if the Purifi modules are fine with this.

I don't have these ESL63's as I wrote, but completely rebuild one's. They sound a way better than the ones that came out of the factory in the 80th's.

 

[voodooless]

I don't have these ESL63's as I wrote, but completely rebuild one's. They sound a way better than the ones that came out of the factory in the 80th's.

That makes no difference whatsoever. Al ESL is basically a giant capacitor, no matter if it’s rebuilt or not.

The original would already provide an above spec capacitance at 20 kHz. Now these amps are fairly robust so probably not an issue. I would still check this just to be sure.

 

[antcollinet]

I just read and saw bad reviews about the sound quality of the Fosi Audio P4.

Almost certainly audiophile snobbery combined with sighted listening.

The measurements tell us that what comes out of it is the same as what goes into it. The only way it can have bad sound quality is if what goes into it has bad sound quality.

 

[LTig]

I have read that every pre-amp has an own character.

Yes, there is a lot of misinformation spread by audio mags and manufactures alike. Do not trust any claim which is not backed by hard measurements. I for example stopped reading audio mags many years ago, and on stereophile.com I read only the specs and measurements pages. They tell me enough.

In that case I have to try several pre-amps in my system. I don't want a warm or what ever sound.

Warm sound means a loss in mids and highs which can be measured easily. If the frequency response is flat - and this is the case for all properly designed preamps - there is no "character".

Also there must be a sound match between pre- and power amp.

Not with properly designed amplifiers.

I sold the Spectral DMC12, because of his terrible sound. I borrowed a passiv pre amp from a friend, and the results were very good. But that thing costs 1500 euro and had a knob for left en right.

And as I've written above - you cannot trust your hearing without proper controlled auditions. Doing it is a humbling experience - been there, done that - but is very revealing.

I have a Kuzma + VandenHull The Frog + Sphinx phono amp. A Philips drive + Weiss Dac 2.

My recommendation: go with @antcollinet's advice.

 

[Wil]

I almost forgot to thank everybody for their help.

 

[Sir Sanders Zingmore]

I sold the Spectral DMC12,

The Spectral has a bandwidth of DC - 12MHz (not a typo).
Is it possible that ultrasonic signals might not play nicely with Class D amps?

 

[Wil]

The Spectral has a bandwidth of DC - 12MHz (not a typo).
Is it possible that ultrasonic signals might not play nicely with Class D amps?

The Spectral played only with my Ayre V6. He accentuated the high tones.
In a shop the Spectral DMC12 was combined with a Spectral power amp, dull sounding Avalon speakers and Mit cables with a network inside. That gave a great combination. But that looks like a solution of problems.
In een older set-up here the DMC12 did a good job with valve mono blocks on Dutch Millon speakers.
At the importer of Magnepan, my DMC12 killed his own brand power amp(10.000 euro) there.
Some people say it all has to do with the bandwidth you mentioned to. I am not technicall at all.
The class D Audiophonics sits still in his box. I waight until I have a decent pre-amp, whatever it will be. Maybe tomorrow a Rotel.
I don't wanna risk my new Quad speakers and don't like fireworks in the listening room.

 

[Wil]

Thanks for the technical insights. For my setup, I’m going with a Rotel RC-1550 to experience it in my own system.

 

[antcollinet]

Thanks for the technical insights. For my setup, I’m going with a Rotel RC-1550 to experience it in my own system.

That looks like a good solid choice. And reasonable prices on the used market. Plus if you decide it is not for you, you lose little to nothing at resale.


EDIT : A couple of things to note:

1 - It appears to have a gain of about 15dB from looking at the specs (input sensitivity 170mV vs nominal output of 1V). You will probably want to set your amp to it's lowest gain setting (12.5dB if I am looking at the correct 450). This will give you a system gain of 27.5 dB which should be about perfect. You can always increase the amp gain by one setting (to 20dB) in the pretty unlikely event that it doesn't go loud enough.

2 - The Rotel has a built in phono preamp. It might be interesting for you to compare that with the Sphinx, though the gain is on the low side for your MC cartridge.

 

[Wil]

That looks like a good solid choice. And reasonable prices on the used market. Plus if you decide it is not for you, you lose little to nothing at resale.


EDIT : A couple of things to note:

1 - It appears to have a gain of about 15dB from looking at the specs (input sensitivity 170mV vs nominal output of 1V). You will probably want to set your amp to it's lowest gain setting (12.5dB if I am looking at the correct 450). This will give you a system gain of 27.5 dB which should be about perfect. You can always increase the amp gain by one setting (to 20dB) in the pretty unlikely event that it doesn't go loud enough.

2 - The Rotel has a built in phono preamp. It might be interesting for you to compare that with the Sphinx, though the gain is on the low side for your MC cartridge.

The Rotel is for sale for 250 euro. I wanna go there (5 minutes from my home) and make an offer about 200 euro.
If the Rotel is oke" I will connect him at first with the Ayre and the Magnepan 1.6QR. When everything is fine, I wanne connect my new Quad ESL63. The demo's I had here did a very good job, with the borrowed passive stage.
After that the AudioPhonics, who is adjustable. Later a friend will connect the seperate bought op-amps. So I take my time and go in little steps.
In two weeks the 50kg stone plates for under the Quad will be ready. They are 5cm(more tham 2 inches) thick and measure 60x60cm(2 feet x 2 feet).
In the speaker stands are going heavy iron fillers.

 

[antcollinet]

I will connect him at first with the Ayre

If your Ayre has selectable gain - you should probably set that towards the low end also.

 

[antcollinet]

I cannot listen to specifications. I listen to music.

That is a typical response you are hearing from the typical audiophile world. We get it here all the time.

Point is though - the specifications tell how well a device will handle the music - how much it will distort it (never a good thing) or add noise (equally bad).

 

[LTig]

In two weeks the 50kg stone plates for under the Quad will be ready. They are 5cm(more tham 2 inches) thick and measure 60x60cm(2 feet x 2 feet).
In the speaker stands are going heavy iron fillers.

Just a short note: The material of the stone plate (or stand in general) has much less influence on sound than how much it changes the vertical position of the speaker. Try with shelfed books ...

 

[Wil]

That looks like a good solid choice. And reasonable prices on the used market. Plus if you decide it is not for you, you lose little to nothing at resale.


EDIT : A couple of things to note:

1 - It appears to have a gain of about 15dB from looking at the specs (input sensitivity 170mV vs nominal output of 1V). You will probably want to set your amp to it's lowest gain setting (12.5dB if I am looking at the correct 450). This will give you a system gain of 27.5 dB which should be about perfect. You can always increase the amp gain by one setting (to 20dB) in the pretty unlikely event that it doesn't go loud enough.

2 - The Rotel has a built in phono preamp. It might be interesting for you to compare that with the Sphinx, though the gain is on the low side for your MC cartridge.

When I had the Quad demo speakers here and the borrowed stage, the sound level with the Ayre was not enough. The Rotel is of course a pre amp, so I don't expect that problem.

 

[Wil]

If your Ayre has selectable gain - you should probably set that towards the low end also.

No, the Ayre hasn't. He is for sale.

 

[Wil]

I have not bought a pre-amp till now. What do think about an Audiophonics AP310? It costs here 349 euro.

 

[antcollinet]

I have not bought a pre-amp till now. What do think about an Audiophonics AP310? It costs here 349 euro.

I can't find any measurements for it. More disappointingly, Audiophonics don't give any figures for noise or distortion - so it is impossible to say how it performs.


It does get user ratings of 4.9 out of five from user reviews. It will probably be fine.

 

[sergeauckland]

I can't find any measurements for it. More disappointingly, Audiophonics don't give any figures for noise or distortion - so it is impossible to say how it performs.


It does get user ratings of 4.9 out of five from user reviews. It will probably be fine.

The manual states that the chip used is a LM4562, which has vanishingly low levels of distortion and noise, so unless they've totally screwed up the implementation, I would expect the specs to be good.

S.

 

[Wil]

I can't find any measurements for it. More disappointingly, Audiophonics don't give any figures for noise or distortion - so it is impossible to say how it performs.


It does get user ratings of 4.9 out of five from user reviews. It will probably be fine.

That's not very clever of them. According to me, you start with measurements, you look at the quality of the used components, finally you wanna hear a product. Friends have their 400 amp and are very enthousiastic about Audiophonics.

 

[antcollinet]

The manual states that the chip used is a LM4562, which has vanishingly low levels of distortion and noise, so unless they've totally screwed up the implementation, I would expect the specs to be good.

S.

But that is the point of measurements, isn't it? It is easy to select the best-performing chip - yet mess up design hygiene (layout, wiring, component selection) to dramatically compromise that chip’s performance. Measurements tell us if the manufacturer has got that right.

And here, Audiophonics presumably haven't even measured themselves - since they provide no figures of any kind, which is a bright red flag in my book.