The price is right....or is it?

[Firebottle]

Perhaps the Croft uses the Teldec (Telefunken/Decca) response curve. This replaces the 75us time constant with a 50us one.

After further research I now know that Glenn uses passive equalisation in the 25R but way off standard RIAA curves.
The lower turnover of usually 3180 uS is something like 5700 uS, whilst the upper turnover is way less than the normal 75 uS, or even 50 uS.

No wonder there was a tonal difference

[Marco]

Interesting, Alan. Do you know if that also applies to older Croft preamp/phono designs, such as the Epoch and Charisma, or simply to the current models, such as the 25R?

Marco.

[Firebottle]

I don't know about the older ones I'm afraid Marco, can you get a local techie to trace out the equalisation network?

[Marco]

Sure. I'll probably have that done when I get my new Khozmo stepped attenuator fitted. It's no biggie - just curious why, to my ears, the phono stages in Croft preamps always sound so good (better than most others I've heard), and perhaps the RIAA curve, chosen by Glenn, is partly responsible for that.

I've not listened to your designs, though!

Marco.

[DSJR]

Older croft models from the late 80's/early 90's were extremely accurate on the RIAA from 10Hz or so out to 20kHz, when the response rose slightly (the rest well within half a db). I'm amazed if current models deviate so much more, although Stereophile supposedly found errors which had Glenn steaming apparently. Don't know what happened after..

Does this help - featuring my very own Croft preamp before being sold to me Circuit of PP model drawn, only the posts in mine are actually 1M log rather than 500k log.

http://www.southampton.ac.uk/~apm3/d...t_preamps.html

[Marco]

Cheers for the info, Dave. You know me with measurements, though... I don't really give a toss. Ultimately, it's about what sounds best!

Marco.

[K3vin]

I've just scanned throught this thread (I'm meant to be doing something else) but I thought I'd make a couple observations:

When I was in the industry many UK manufacturers worked on a 10 to 1 rule- whatever the 'material' cost of a component is will it will end up retailing at 10x that amount.

That might sound like a large profit, but it isn't, given that (at the time) the manufacturing process was very labour intensive (especially at naim), most were making large investments in equipement (Linn had just bought a flow solder machine and a surface mount machine) and there are many mouths to feed along the way- not least HMRC who probably took the biggest slice of the pie in truth.

I can't speak for today, especially as a fair few bits of kit are built offshore, but no doubt (in my mind) price has overtaken sound quality, however, I see the positive side of this too...

I will not be going out and buying the next box in the chain because there is a manufacturers path laid out for me to follow (according to whoever's 'house sound' you buy into) I am now forced (gladly) into thinking for myself, getting the best I can from many sources, and making use of the great number of second hand and often un-loved items out there. And, I will enjoy doing it- this is a hobby after all, not a race to the top of the food chain.

Re: music lovers v's hifi enthusiasts- having a good collection of well recorded discs that are loved and enjoyed by an enthusiast trumps the guy with 1000s of 'okay' discs that never get looked after nor have seen the light of day in years- what's the point in that? The latter is probably listening to MP3 now anyway.

I did note tho', that the better a guy's system got, the smaller his (listened to) material got, because poor recording/engineering doesn't get better with the equipement- it gets worse.

I did a dem with a couple of guys (one musician and the producer) who are in a well known UK (Oxford based) rock band, we played their latest album which was not yet released on a Gyrodeck and they were very dissapointed to say the least!

I had to break it to them that the Gyro was telling it the way it is, and that their recording was to blame, and I followed it up with proof when I put on a Buddy Holly track recorded in the 1950s which just blew them away. They both bought good Gyro based systems.

As an aside- when I installed the Gyro in the band member's home, there was a burnt 'Grammy' award sat in the fireplace grate- rock and roll.

[hifi_dave]

Cheers for the info, Dave. You know me with measurements, though... I don't really give a toss. Ultimately, it's about what sounds best!

Marco.

Sometimes, politics get in the way.

[fiddlemaker]

After further research I now know that Glenn uses passive equalisation in the 25R but way off standard RIAA curves.
The lower turnover of usually 3180 uS is something like 5700 uS, whilst the upper turnover is way less than the normal 75 uS, or even 50 uS.

No wonder there was a tonal difference

but wouldn't this difference in upper turnover give less hf rolloff, not more as stereophile claim to have measured?

[Firebottle]

The eq network is actually a little more complicated, I was just summarising.

I guess what stereophile claim is an accurate portrail,

Alan