Conrad Johnson Pre-Amp ET-6

[Tomas]

When I first got my ET-6 it was for use with a moving magnet cartridge. I sent it back to be adjusted for a moving coil. I had just purchased a Linn Sondex LP 12 with a Graham Custom Tonearm and a Benz Cartridge.

I would like to be able to play my other (stand by) Project Carbon Turntable but it has a Moving Magnet cartridge. I tried plugging it in with the MC adjustment but the sound was unsatisfactory. Do I have to send the ET-6 back to be able to use the MM cartridge?

I have a Audio Research Pre-amp SP-9. Could I plug the MM into the Phono Input on the Audio Research SP-9 and then plug the Audio Research Pre-amp in to an input (video, Aux, etc.) on the CJ-6?

All suggestions and responses will be greatly appreciated. Also, is there a recommended change from the Benz to a suitable Moving Magnet Cartridge?
should I wish to change in the future?

Thanks, Tomas

[admin]

If the cartridge has an ouput outside of the ET-6 input range, then the sound is going to be less than satisfactory. You can always use another phono stage to get the signal to line level and then run that into the ET-6. But that is simply like using another phono preamp, so it's not right or wrong.

[AnotherJohnson]

When I first got ET3SE, I used one of my PV preamps as an MM phono, running the tape out (line level) to a line level input on the ET3SE. It was fine.

I also, at various times, ran Rega and Naim MM phono preamps of modest cost for MM cartridges.

With my first acquisition of a Lyra Delos, I stopped thinking any of my MM cartridges were worth a listen, and I abandoned the desire for MM listening.

The TEA2 and TEA1 pushed MM off the table, although they can be reconfigured to lower gain.

All this stuff is a lot of fun to play with. Enjoy!

[Tomas]

Thanks for the information.
Much appreciated and will try.

Tomas

[Tomas]

I would like to clear what I think I heard about using another pre-amp for a MM Cartridge and being able to use my CJ ET-6.
I would plug in my Pro-ject Turntable with the MM Cartridge into another Amp ( my Audio Research SP-9) into a Tape Input and then from the Audio Research SP-9 Output (Record) into the CJ ET-6? Could I also plug the Project into say another input like the Video or Spare and then from what Outputs of the AR SP-9 ? I guess I am asking if it has to be the Tape In and Tape Out sections of the AR SP-9. Would you ever use the Main Output?

Sorry to sound so dumb but it is better to ask then to screw up by not knowing.

Thanks,

Tomas

[AnotherJohnson]

The MM’s phono leads from the TT go to the phono in of a phono equalization equipped preamp.

You come out at line level by using the tape out jacks. The main out jacks are volume controlled. The tape out jacks are not.

You then go from tape out on the preamp that has the phono section into any of the line level inputs on the other preamp.

Then main out to your amp.

That will give you normal line level performance from stuff plugged into the ET6, and it should not be much degraded from normal phono operation with the SP9.

[Tomas]

I have a question about Linn-Sondex LP12.
I love the sound with the Conrad Johnson ET 6 Pre-amp and ET 120 amp. ( Graham Custom Arm and Benz Ruby MC)

Does anyone know which model of Linn I might consider that does not need to be wall mounted?
I have tried all the things for keeping it from having floor vibrations interrupt play and none of them are satisfactory.

Thanks,


Tomas

[AnotherJohnson]

Linn do not recommend wall mounting. Yet I prefer it myself, and my high spec LP12 is on a Target wall Mount from back in the day.

My other LP12 is on a light table as Linn recommend. They both sound great, but the flexing floor can require careful approach or retreat for any turntable.

All LP12s have a sprung subchassis, and if it is set up correctly, which is no mean feat, it is less sensitive to footfall.

Most modern turntables do not have a sprung subchassis. My experience with VPI and Levinson tables that were not sprung, is that they suffer from footfall issues too if the floor flexes. Perhaps the best TTs for ignoring their mounting that I have owned have been the VPI HW19s from the late ‘80s. But I seriously prefer the well set up LP12s.

The best thing you can do for any TT is to set it up where floor flexing is not a problem. I like either wall mounting, or a concrete (or other) fixed floor.

[admin]

Tomas,

Can you tell us a little about the room and TT setup as you typically have to have pretty significant vibration to interrupt play (ie needle skip). My listening room is above a garage and the floor was pretty sensitive to vibration and movement. I ended up bracing the floor from underneath and it helped tremendously. Also, have you tried putting the TT on something very heavy like a slab of marble? Sometimes bracing with a heavy stand and some good isolation feet can do wonders.

[Tomas]

I have a fairly large room with wood floors. The cabinet is solid with shelves below for my CJ Preamp and Marantz 8006 CD player and another CD Player by California Audio Labs, as well as a Nikamichi Cassette Player. It is not a flimsy cabinet. I have braced the cabinet with wood shims because the back area is slightly different in level. (To make sure to top surface and the TT are level.). I had a TT specialist calibrate the cartridge for the correct weight and adjustment . It is a Benz Ruby MC.

I did put a one inch and a quarter think piece of granite underneath the turntable but it did not help. What do you mean by a light table?

My Main system is CJ ET-6 Preamp. CJ Classic 120 Amp. Aerial 10 T Speakers, Linn Sondex LP-12, Graham Custom Arm, Benz Ruby MC Cartridge , Marantz N8006 CD, California Audio Lab CL 15 CD, JL Audio e 112 Subwoofers (2), Cardas Cygnus Speaker Cables (bi-wired), CardasCygnus Interconnects.
Nakamichi 680 Cassette

[admin]

Sounds like you have done a lot of work on this. I admit I am running out of ideas. I have one recommendation that you may want to try. I buy acoustic treatments from this company called the foam factory. Really good prices and no BS. I would recommend you buy a slab of 2" thick Neoprene foam to cover the area of the marble slab you put under your turntable. You can ask them to cut it to a specific size for you.

https://www.thefoamfactory.com/closedce ... prene.html

This is a very dense foam. It may be enough to dampen the small vibrations that are reaching the TT. It's a relatively cheap thing to try and maybe you get lucky. If that fails I think we have to talk about reinforcing the subfloor... which is not easy or cheap.

[Tomas]

I want to thank everyone for their recommendations and suggestions regarding the vibration directly related to my Linn-Sondex LP12.
Having remembered that it was advisable to use either a very heavy dense base/support for the Turntable or a very light base, I decided to try the
light weight base/support.

I had a slim legged side table with a square top so I placed the Turntable on this. I placed a record on and queued the cartridge and stepped back to
my seat. I couldn't believe it!!!! No skipping when I walked across the wood floor and no interrupting of the music in any way.

So I also had a metal legged base which was expandable so I placed my heavy 1 inch and one quarter granite top on this. I do the leveling as before
with the wood table and then placed the Turntable on the granite top. And again, no skipping of the cartridge or interrupting of the music.

So, my good luck is that the lightweight table/bases worked for me. I decided I liked the look of the metal leg table with the granite on top so that
is what I have been using since.

I have attached pics of both tables. The dimensions are side table height and the tops are square rather than rectangular.

Thanks everyone!!!

Tomas

[AnotherJohnson]

Great result!
Congratulations!

[admin]

Great news. Glad it's solved with a simple and inexpensive solution!

[Q3Di]

I use 3" thick precision granite plate as a turntable platform.

[Tomas]

Cartridge question

I have an additional turntable and it has a MM Ortofon Bronze on it. In order to use it on my CJ ET-6 Preamp which has been adjusted for a MC cartridge. I would appreciate recommendations for a MC replacement. The turntable I am speaking of is a vintage Pro-ject Carbon . I’d like to play both turntables without having to put in a phono pre-amp to hook up to the CJ ET-6

[admin]

Sounds like you are looking for a step up/down transformer for the TT cartridge. It will allow you to equalize the outputs so you can use the same phono preamp.

[AnotherJohnson]

I had an Ortofon cadenza bronze MC cartridge that many people liked.

Lots of folks like the Hana line.

My favorite “budget” MC is the Lyra Delos.

[AnotherJohnson]

I suppose it should be observed that the arm is to be matched to the cartridge due to the dynamics of the combined arm cartridge system.

You want to keep warped records from exciting a first natural frequency.

[AnotherJohnson]

FWIW, it is relatively inexpensive to try the Rothwell in-line attenuators. They are available in different attenuation levels. They can be found on eBay. RCA compatible models are typically under $60/pair unless prices have changed recently. Install them on the phono leads between the TT with the MM, and the phono in Jack’s on the preamp.

I just checked. $54 + $7.55 shipping for a 10 dB pair.