CJ Premier 17LS2 vs ET5/7


I enjoy a Conrad Johnson Premier 17LS2 that is paired with a McCormack DNA 500 and Thiel CS5 speakers.

My problem is that the 17LS2 has an output impedance that can rise to 1600 ohms on the low end. The DNA 500 has an input impedance of 10,0000 ohms so I suspect that I am missing the last bit of bass. 

When I listen to other preamps with a lower output impedance, the bass goes a bit lower, but I sacrifice musicality and nuance.

My thinking is that, if I like the CJ sound, an ET5/7 with 100 ohm output impedance would get me that last bit of bass without losing the musicality and nuance.

Has anyone listened to these preamps and can tell me how the ET5/7 sounds compared to a 17LS2?

Thanks for listening,

The quick answer is ET5 over ET7... read on as to why I feel this way. 
Yes, I have both pre's now and have had the ET7, and Gat series 2. I have a Premier 17LS/ LS2 and Premier 16LS2. 
There are a few ways to go here. ET5 for the money I bought mine for $3000 is then for me the reason I got rid of the ET7 and GAT series 2. For the money its as good. As for superiority of which the GAT2 yes has it over. However the incremental differences in dollars, ET5 also wins over ET7. There is a ET7 series 2 now since early summer and no I have not listened to it. The 5 is an excellent pre, has more in it than the 7 (in my opinion they stretched the 7 too thin, took out some things that they later found out they needed and... now there is a 7 series 2. The Bass in ET5 is wonderful. Just do yourself a favor, don't go hog wild on Tube swapping with out knowing that CJ sets bias high to get the most out of things so not every tube will do well and will burn out earlier than anticipated. So, I am using an AMPREX and a Genelax Gold Lion; lots of bass.   Now, another suggestion is to look to move to a CJ tube amp set up. With the right one, the Bass will be there and the mid-range/highs.   
A side note; the Premier 17 is in no way a slouch, is in every way one of the best CJ pre's ever. Try the 6922 Genelax Gold Lions and you'll find something new maybe. 
Hi jahattl513,

You have mentioned the Gold Lions before so maybe I should give those  a shot before changing the preamp.

I appreciate your advice.

Thanks for listening,

Hi Dsper,

Our systems are similar, I am driving Thiel CS6’s with Mcintosh 501’s that also have a 10K input inpedance. In the past I have used CJ Premier 14 that has a similar output impedance situation to your 17LS2. After switching to an ET5 the first thing I noticed was a significant increase in bass.

Also transparency and clairty which I attribute to the teflon caps, but the 14 is known for having a bit of the old CJ golden sound.

jahatl513 has good advice on tubes, the ET5 is a tube eater. I have been though several EH6922 which CJ supplies, also Philips ECC88 which CJ also supplies. The Philips lasted longer that the EH. I have a Seimens ECC88 I have not tried yet, it is supposed to be a tough tube. I have also heard great things about Amprex.

Frankly, I like the EH 6922, it just gets noisy after a couple hundred hours. Keep us posted on your journey.


hi pops,

Thank you for the info. The 17LS2 has the Teflon caps and it is very good. I inserted Phillips ECC88's and they seemed to clarify the sound - more clear.

Thanks for listening,

I have heard the ET-3SE mated w/ the Classic -Sixty power amp in a B&W / Audioquest system. The sound was liquid and sweet from top to bottom. Very musical and pleasing sound.  The ET-5 is on my list to demo.
Happy Listening!
I have a CJ MF2275 mated to the ET-5, I moved up from the ET-3SE. Both pre’s are very good, but after settling in with the ET-5, I don’t see any need to change my system anytime soon. I am very content with my primary system.

though I am working on my second system. I might really like this hobby too much.
I'm about to receive a ET-5. I currently own a ET-3 SE. Kevin Deal from upscale recommends the Russian tube 6N23P. I have several vintage from Reflektor as well as the Voskhod plants. I've also seen the Mullard E188CC recommended. Will be looking forward to checking the differences.