Page 2 of 2

Re: new ET-7, the replacement for the ET-5

Posted: Tue Aug 22, 2017 12:32 pm
by roberto
Second little review:

My ET-7 is showing good things now. The first thing is a crystal clear highs, with outstanding resolution. There is no miasma at all!. (Placido Domingo, Anna Netrebko and Rolando Villazon at Berlin Concert). Voices are projected with the right energy, no sore throats, and the harmonic texture is just right! The string instruments have their warmth and magic.(Salvatore Accardo playing six Paganini violin concerts). The piano shows the reverberation of the room, and the coherence between lower register notes with the upper octave is truly amazing (Valentina Lisitsa playing at The Royal Albert Hall). The way that the piano player hits the notes, is what you do get. The nuances of the music are breath taking. Truly sense of 3D. The bass is robust but without losing its physical size.(Bryan Bronberg Wood). There are a lot of air into the wind instruments, with the right size too. The trumpet is warm (Chirs Botti at Boston) and also the percussion. ( Quality of Silence by Steve Davis).

This is a remarkable preamplifier, and along with its brother the Classic One Twenty SE, the overall sound is quite impressive. I really do like a lot what I am hearing or should say: LISTENING!

Re: new ET-7, the replacement for the ET-5

Posted: Tue Aug 29, 2017 12:53 pm
by plurn
roberto wrote: Sat Aug 19, 2017 3:29 pm Here is the inside pic of the ET-7.
Hi Roberto,

Thank you for posting the inside pic. I have not noticed any other website having a picture of its insides so maybe conradjohnsonownsers.com is first.

When I compare the insides of the ET7 to the ET5 I am a bit surprised. ET7 has a lot less big white capacitors and has more electrolytic capacitors than the ET5. Also the tube is now on the main board rather than on a vibration isolated daughter board. Just looking at estimated cost of parts, I would think the ET7 would cost Conrad Johnson less to build than the ET5. That is good engineering.

Anthony

Re: new ET-7, the replacement for the ET-5

Posted: Tue Aug 29, 2017 1:18 pm
by plurn
Bill Stevenson wrote: Tue Aug 15, 2017 1:37 pm How much gain does the ET-7 have? The spec for the ET-5 is 25 db, which probably accounts for the relatively shortened tube life before noise. I love my ET-5, btw. Just wish it were not so hard on the tube. At least it is only one tube. If the ET-7 gain spec is lower, say 20 db or so, we can speculate that tube life will be better.
Conrad Johnson has put the ET7 page online now. Same gain as the ET5 at 25dB, as well as most of the other specifications being the same. Only difference is the ET7 case is a bit less tall, and the ET7 weighs 9 pounds less.

I don't think there is much that Conrad Johnson can do to reduce the gain while using the 6922 tube so it makes sense that it is still the same as GAT/ET5/ET3. The typical way to reduce gain, as I understand it, is to use negative feedback and I think it is against Conrad Johnson's philosophy to use negative feedback.

The ET5 also has quite high heater/filament voltage of 6.57V which is at the very upper end of what is acceptable for 6DJ8/6922 tubes - really pushing it. This is another factor that can reduce tube life. Perhaps they have reduced the heater voltage for the ET7 to normal levels (6.3V)?

If you want a less problematic tube for your ET5, the Philips PCC88 (same as used in GAT 2) are long lasting. They are designed for higher heater voltage.

http://conradjohnson.com/et7-enhanced-t ... amplifier/

"Specifications
Gain: 25 db
Maximum output: 20 vrms
Output impedance: 100 ohms
Distortion: less than .15% THD at 1.0 V
Frequency response: 2 Hz to more than 100Khz
Hum and noise: 100 db below 2.5 v
phase: inverts phase of all inputs at main out
Tube complement: 1 x 6922

Dimensions
15.375D x 19W x 4.375H inches

Total Weight
19 lbs."

manual:
http://conradjohnson.com/wp-content/upl ... manual.pdf

Anthony

Re: new ET-7, the replacement for the ET-5

Posted: Tue Aug 29, 2017 2:33 pm
by Bill Stevenson
Thanks for the followup Anthony! I bought 2 of the Phllips PCC88 tubes from cj and agree with you that they held better than others I have tried before they went noisy. My ET5 is now 3 years old and gets a lot of use. I love the sound of the thing and go through about 2 tubes a year in it. Right now it has a Genalex Gold lion in it, which sounds really the best of any I have tried, but it only has a few hours on it so far. The thing is, the ET5 sound tickles me to death so if all it takes is an occasional new tube, I guess that is how it is going to be. But needing a new tube in under one year is unique in my experience. By contrast, my TEA2MAX and ARTsa both go 2 years easily between tube changes and even then the new tubes don't make as huge a difference.

Re: new ET-7, the replacement for the ET-5

Posted: Tue Aug 29, 2017 5:46 pm
by roberto
Hola Anthony and Bill. All I can say is that the ET-7 sounds very different than the ET-5, specially at the wide stage and the depth of the stage. Instruments are projected with an incredible sense of live performance, with outstanding clarity.

If you want, I could ask Jeff Fisher the difference between them...

Happy listening!
Roberto.

Re: new ET-7, the replacement for the ET-5

Posted: Tue Aug 29, 2017 10:33 pm
by ronenash
To me the ET7 seems to be built to a much lower and cheaper standard than the ET5. For year a cu took pride in the fact that they are not using electrolytic caps in the signal path and it's related power supplies. That no longer is the case. I can't comment on the sound of the ET7 but parts costs are definitely much lower than the ET5. It would be interesting wheat what Lee Johnson has to say about these design choices.

Re: new ET-7, the replacement for the ET-5

Posted: Fri Sep 01, 2017 1:56 pm
by Bill Stevenson
I have no opinion concerning the sound of the ET7 since I have not heard one. I will say again that I really like the sound of the ET5 and if the ET7 is quite different that would not necessarily tempt me into wanting to find out more. Actually, the ET5 sounds pretty much that same as the GAT on small group, acoustic music, which is what I listen to most of the time. The GAT does have slightly greater impact on large ensemble recordings. What I hear on my system, in my room is the recording artist like she is standing right in front of me, with the piano behind her. Palpable, like you could reach out and touch her. A wider, deeper, sound stage would improve things for me how? I am reminded of an old story about a salesman who was pedaling a new invention, the chain saw. He would drive around in rural, wooded areas looking for men cutting wood by hand and when he spotted them stop his car, get out and demonstrate his superior invention. One day he did this with an old man who seemed singularly unimpressed. Flabbergasted the salesman asked him why. Answer: Don't need more wood. like cutting wood for exercise and don't have anything else to do anyway. With respect to what kind of capacitors are employed inside, that is about as important to me is the kind of trees that the pulp comes from that are used to make the corrugated shipping containers used by cj.

Re: new ET-7, the replacement for the ET-5

Posted: Fri Sep 01, 2017 10:04 pm
by roberto
My history is that I had long time ago, one ET-5, if you do a search here, you will find one of my firsts posts here...and I was in heaven as you are, but I had to sell it, because I had to help my mom with an illness, and I needed the money. Now that I have the ET-7, I am very happy with it too. The signature of C-J is here, no doubt about it.
Teflon capacitors have a property to keep the same capacitance in all voltage ranges. This makes them very stable...a reason why C-J uses them. The metal foil resistors help the S/R. MIcro-dynamics is the clue, I think. Also, very sense of 3D, with the right energy at the percussion instruments.
Right now, I am a very happy man enjoying C-J sound in my system. Out there are better products, and also C-J makes them. All I can say is, these new products, the Classic One twenty SE and the ET-7 have a synergy that my ears truly enjoy them. I never had said that these units are better than other C-J product. What I am saying is: just give them a try, there is nothing to lose. Perhaps you might like them as I do.
I wish to you a very happy listening!

Re: new ET-7, the replacement for the ET-5

Posted: Tue Sep 05, 2017 11:24 am
by roberto
Dear friends, I asked to Lew Johnson your concernings between the ET-5 and the ET-7. Here is his response about this:

Dear Roberto,

It is true that the power supply filter capacitors in the ET7 are now electrolytic capacitors rather than polypropylene - with resulting increase in total capacitance, but the post-regulated power supply storage capacitors continue to be Teflon capacitors. Resistors in the audio circuits and related power supplies continue to be Vishay bulk metal foil. So hardly a "much lower and cheaper standard". And the ET7 features the revised voltage regulator circuit from the Series 2 GAT, a worthwhile improvement in its own right.
best regards,

Lew Johnson.


As you can read him, the ET-7 is a step forward of the ET-5. It is designed taking in care the series 2 GAT...
My advice is, take a little time and go to a Conrad Johnson dealer for a demo of the ET-7.
Happy listening!
Roberto.

Re: new ET-7, the replacement for the ET-5

Posted: Sun Sep 10, 2017 10:10 pm
by Big Dog RJ
Act1, Act2, Gat1, Gat2, ET5, ET7...

just follow my path and get a CAV45- don't have to worry about another preamp for good, ha!

RJ

Re: new ET-7, the replacement for the ET-5

Posted: Mon Sep 11, 2017 3:46 am
by roberto
Hey RJ, understood perfectly. All CJ products are that good ! CJ sounds right!
Happy listening!

Re: new ET-7, the replacement for the ET-5

Posted: Wed Oct 11, 2017 1:01 pm
by roberto
Follow up...

My ET-7 is now fully broken-in, and I can say that it is singing like a very expensive canary. Where I am listening a big difference is at the human voice. Here it shines like a 24 Karat gold. Its smooth, having silky strings, and tons of definition. Truly sense of 3D, with outstanding huge stage. The musical instruments are placed in a believing space, with much air between them. The decay on the piano musical notes are like to live performance. The communication between the musicians is truly achieved, and you can feel their fun playing together. It is giving to me a truly magical journey deep into my heart. The emotional is granted easily, with much expression on every musical note. I am truly that happy.

The ET-7 along with the Classic One Twenty SE power amp, is breathtaking with the quality of their sound together. They do a truly magical synergy, and their sound revival many other good brands with much more expensive units.

Thank you Conrad Johnson for giving us these quality units for the listening pleasure that we are getting!
Happy listening!