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View Full Version : I'm a lucky boy - new C-J ET3 preamplifier.



AlexM
22-05-2014, 16:18
Yes, indeedy, I am a happy chappy... I have upgraded my C-J PV15 preamp to a C-J ET3.

https://farm6.staticflickr.com/5076/14244790814_5df22a1fe0_c.jpg (https://flic.kr/p/nGLh2C)2014-05-22 15.49.35 (https://flic.kr/p/nGLh2C) by alexmastersuk (https://www.flickr.com/people/14548229@N07/), on Flickr

The ET3 is a simplified dervative of the circuit in the statement GAT preamp - circuit topology is similar, but without the expensive and complex power supply arrangements, and very high end resistors, capacitors and other passive components. The line stage uses a single 6922 for voltage gain, and a MOSFET buffer to ensure a low output impedance. The gain seems to be quite a bit higher than my PV15 - maybe this is because no feedback is used. Volume control is by relay controlled resistor ladder, and the preamp has full remote control.

There is a seperate MC phono board using 3x 12AX7s that is a close relative of the TEA1 stand-alone phono stage that can be seen on the left hand side of this picture

https://farm3.staticflickr.com/2901/14244797104_e43a489025_c.jpg (https://flic.kr/p/nGLiU5)2014-05-22 16.11.36 (https://flic.kr/p/nGLiU5) by alexmastersuk (https://www.flickr.com/people/14548229@N07/), on Flickr

First impressions - wow! the ET3 blows the doors off my PV-15. I had quite high expectations, but it really is quite a big step up. I think that it is true what they say that you don't know how good the rest of your system can sound unless you have a top line pre-amp.

Listening to the SB Touch via the Cambridge Audio Azur 851C CD/Dac, first impressions are that the soundstage is now W-I-D-E, extending well clear of the speakers, and and appreciable height and depth. On acoustic recordings you can really get a sense of a group of musicians performing in a space and being able to hear what was only hinted at - echos and reverberation cues give a spookily realistic sense of a being in a defined volume of space.

High frequency detail is outstanding, clean and crisp, and this is the best that I've heard cymbals from a digital source. You can hear exactly where a ride cymbal is being hit, on the bell or on the rim and exactly how hard. It makes precussion tracks fascinating to listen to because there is so much going with the playing of a drummer like Dave Weckyl that I didn't appreciate before.

In the mids, voices sound natural and well defined, and there is a sense of each instrument in the recording doing it's own thing and being easy to pick out, with realistic timbre and dynamic envelope. Sounds like brass stabs start and stop in a totally believable way, and despite the detail/resolution the overall sounds blends together as a performance rather than being disected in a weird 'Hi-Fi' way. There seems to be an impression that louder sounds dominate quieter ones less than before - less blending and modulation of decays by 'foreground' sounds.

Bass performance is weighty and powerful, without being soggy or boomy in any way. Electric Bass, Acoustic bass or left hand piano just sound right to me - plenty of weight and heft, with believable texture and envelopes. Hearing a five string bass played on something like Donald Fagin's Security Joan from Morph the Cat seems that the lower notes on the B string have consistent weight and a defined envelope wheras before they tended to waffle and become less distinct. I am an ex-bassist so I really appreciate this clarity and dynamics I'm getting at the low end with this pre-amp. I love Brian Bromberg's double bass on Downright uptight.. just marvelous.

So, although I cheaped out and didn't get the even more excellent (and much more expensive) SE model with nice teflon caps and mega expensive resistors I feel that I'm getting a good chunk of it's perfomance. I can upgrade further for the same cost as the price difference, but I think I would need new speakers, turntable etc first. Oh dear.

Cheers,
Alex

Firebottle
22-05-2014, 17:22
All sounds rather excellent, good performance hike without spending mega money :clapclapclap:

.......and valve based, nice.

Alan

AlexM
22-05-2014, 17:32
Cheers Alan,

It was still a lot of money by my standards and those of most sane people. I can't really talk about VFM at this price point, but the sound is very very good and it integrates wonderfully with the rest of my system. It has always surprised that there isn't more love for C-J on AoS given the number of tube lovers here...

Regards,
Alex

julesd68
22-05-2014, 20:02
Congrats Alex, looks fabulous. I'm delighted with my CJ EV1 phono stage and I'm sure I would like their amps too ...

Enjoy!

Jimbo
23-05-2014, 06:15
Cheers Alan,

It was still a lot of money by my standards and those of most sane people. I can't really talk about VFM at this price point, but the sound is very very good and it integrates wonderfully with the rest of my system. It has always surprised that there isn't more love for C-J on AoS given the number of tube lovers here...

Regards,
Alex

Hi Alex,

I have always liked C J stuff for many years and hold them in great respect but they were always out of my league price wise. I have heard some of their earlier models and they were indeed impressive.

Enjoy your new pre:)

Marco
23-05-2014, 07:04
Excellent review, Alex, and a lovely preamp :)

You're right, most of the music is often lost at the preamp stage, if you haven't got it right - and the best valve preamps have a magical way with music that few solid-state (or passive) preamps are able to match.

Enjoy! :cool:

Marco.

Tarzan
23-05-2014, 12:19
Excellent review, Alex, and a lovely preamp :)

You're right, most of the music is often lost at the preamp stage, if you haven't got it right - and the best valve preamps have a magical way with music that few solid-state (or passive) preamps are able to match.

Enjoy! :cool:





Marco.



Why?

AlexM
23-05-2014, 12:34
I think a part of the success with this preamp design is due to no negative feedback being used.
.

AlexM
29-05-2014, 20:15
I have put a Gold Lion 6922 valve in to replace the standard Electro harmonix 6922. Wow - what a good value upgrade!. The sound stage has opened right up and the amp is totally silent (was some slight tube rush before)

There is quite an improvement in mid range and treble detail and bass now has more power.

I've seen a few positive reviews of the GL small signal tubes and I can confirm that they are excellent indeed. I'm very pleased that there is a good new production alternative to NOS tubes, which I have always found to be something of a crap shoot in terms of performance and life. There are still plenty of good old valves around, but it's nice to know that we aren't stuck with second rate modern alternatives or fishing from a shrinking stock of decent NOS valves.

Cheers,
Alex

hifinutt
07-06-2014, 18:11
yes often seen these and wondered why not more about them
what does `phase inverting` mean with these pre amps ?

AlexM
07-06-2014, 22:48
As far as I know, a phase inverting preamp is designed that way as it permits one less stage in the signal path, theoretically improving sound quality through a simpler circuit. Most CJ preamp seem to be phase inverting - not sure if this is a 'tube' thing or whether it is common with solid state preamp also.

The user manual suggests reversing polarity of the speaker cables with a phase - correct power amp, and suggests that there is a significant SQ benefit. Mine is, so I follow their advice, although I haven't experimented extensively to see if this is so.

I like the Gold Lion 6922 very much, not least because it is a very quiet tube. I am also about to try some cryo treated Voshkod 'Rocket' 6N23P - hope they are good... have a very good rep and are cheap. I got them from Watford Valves, and have always had a good experience with what they supply.. tested for noise, microphonics and have closely matched triode sections. If they work well, I'm going to buy a few more to set aside while they are still available!.

Cheers,
Alex

AlexM
07-06-2014, 22:56
P.s. I am using Ei 12AX7s in the phono stage, and I have to say that they are also pretty awesome. Apparently you will have a hard time getting low noise/low microphonics Ei 12AX7, but if you do they are some of the best sounding around, with some comparing them to top notch Telefunkens. I don't know about that but they seem to have great detail, a defined but smooth treble and good balance from top to bottom. Might be worth finding a seller who screens and selects them as they aren't pricey.

Cheers,
Alex

hifinutt
03-07-2014, 19:44
thanks for that , very helpful