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Valve pres with solid state powers , what works

Everywhere says that Croft Micro Zout is less than 300R. Including Glenn Croft.

It has nothing to do with volts in the sense that Old Shatterhand posted. Yes, in terms of what the voltge does, but not in the sense as used - a DAC with 2.25V output.
 
Tony L said:
I’d argue they were very common. In many cases with a typical 2V+ input from a loudly mastered digital source the power amp stage (even of integrated amps) goes into clipping long before the volume control gets anywhere remotely close to the end stop. In some cases before it even gets to 10 o’clock on the knob’s travel! As such not “an old wive’s tale” at all, but a useful way to explain input gain etc.
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Either you "didn't get it", or I explained myself badly, or you are being deliberately obtuse! The entire point I'm making is that when you NEED to use all or most of the vol control due to low input level or insensitive power amp that it is perfectly OK to do so and nothing will be overloaded or "pushing it". In this respect it very much is an old wives tale.
Obviously I'm not saying that nothing can clip, ever!
 
Vinny said:
Everywhere says that Croft Micro Zout is less than 300R. Including Glenn Croft.

It has nothing to do with volts in the sense that Old Shatterhand posted. Yes, in terms of what the voltge does, but not in the sense as used - a DAC with 2.25V output.
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Where do I mention the Croft Micro? I'm talking about the Croft 25. If the Micro is the one with the ECC83 as a cathode follower then Glen Croft is lying if that's what he says. Simple as that. The output impedance of a simple cathode follower is the reciprocal of the transconductance. Do the math... as our colonial cousins say. Oh and OUTPUT voltage is what I'm on about! This is REALLY BASIC stuff.....which is just one of the reasons why I'm sitting here thinking "what the **** is it with these people?!!!"
 
Dave***t said:
The current Croft preamp is called the Micro 25, according to the Croft website.

Cross purposes?
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Possibly.... but Croft model names and what circuitry is actually in the box are not exactly consistent to put it mildly! There certainly was a Micro.. several variants I believe. And there is one that is usually referred to as a 25 or 25R in regulated form... but is sometimes referred to as a Micro 25 as far as I can see...
Either way the ECC83 cathode follower ones cannot be less than 625R Zout (prob between 625 - 700 in practice) and my simulation of the 25 circuit, which has gain, says 3900R with a pretty accurate triode model. Even extreme room for error would still put it between around 3000 and 5000R.
 
As I understand it they are all ‘Croft Micros’, but the current range is the 25 Basic, the 25, the 25R, and to special order, the two-box 25RS. They are all available with and without an onboard phono stage. The further up the range you go the bigger and fancier the PSU and the better component quality, but I think the core circuit remains pretty constant.
 
L&N republican said:
Anyone tried EAR preamp(864) with naim amp such as 160 or maybe 140.My 890 amp generating a lot of heat so it will be nice to have nice cold amp for summer which can drive quad esl's
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I use EAR864 with a Quad909 (with ATC SCM19v2 speakers) and this combination works great IMO. I'm not after the "warm" sound, I like neutral sound and for me this peamp/amp combo works good.
 
I have a late 80s Croft Micro II :)

I really must drag out Jez‘s DIY build from the cellar and try to complete it over summer...
 
I used a Croft Epoch Elite with an Audio Analogue Donizetti and it was ok. No mismatch. Changed the Donizetti for a VTL ST85 valve and it was better.

Finally got a VTL pre and said bye bye to the Croft. Wouldn't have one back.... ever.
 
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