C2300 Tube Test Day
 

I test my tubes in my gear once a year, usually in June. I have been a bit lax this year, but today I managed to motivate myself into pulling the C2300 out of the living room rack and testing the 12AX7 tubes in the line stage and moving coil phono stage. I have Gold Lion ECC83/12AX7 tubes in the line stage and Telefunken ECC83/12AX7 tubes in the moving coil phono stage. My tube tester for small tubes is the Maxi-Preamp 2 from Maxi-Test. After 15 months daily use of the C2300, both pairs of 12AX7's still tested strong and closely matched. No reason to install new tubes at this time. That's good news. I reinstalled the tubes in the preamp, and reinstalled the preamp in the rack. I love my C2300 preamplifier. It's feature rich, quiet as a mouse, sounds remarkable, built like a tank, and is all analog.


https://live.staticflickr.com/65535/...e3c82737_c.jpg



https://live.staticflickr.com/65535/...00b481f4_c.jpg

Dan,

Could you please tell me who is the stock tubes´s manufacturer in this preamp?

Big differences in terms of sound quality between the stock tubes and the Gold Lyon´s ?

Thank you.

Chema.

I believe the stock tubes are JJ.

Chema.......When the McIntosh C2300 was in production the factory was using tubes made in China. I think they were made by Shuguang. I don't know exactly when McIntosh made the decision to begin using JJ Tubes as their branded tubes, but as I have been told, JJ Tubes are what McIntosh presently uses. I pulled the Made In China tubes out of my C2300 years ago and now use Gold Lion 12AX7 and Telefunken ECC83/12AX7 tubes exclusively. Yes, there is a considerable improvement using Gold Lion tubes. I have no problem recommending them.

Thank you very much, Dan,

Why don´t you use the Gold Lion in the phono section?

Chema.

Chema.......The Telefunken tubes measure about 3dB quieter than the Gold Lion tubes. Both manufacturer's tubes are quiet, but the Teles are the best. I use an Ortofon Cadenza Blue moving coil cartridge in the living room system. It is a low output moving coil. The extra 3dB lower noise floor is an advantage to how quiet the background remains.

Very nice Dan. Thanks for sharing.

Thank´s again Dan,

Using a MM cartridge, the benefits of Tekefunken tubes should be equivalent, isn´t it?

Chema.

Chema.......The higher output voltage of moving magnet phono cartridges negates some of the necessity for ultra quiet tubes in a phono stage. The higher signal levels produce from moving magnet designs deliver a louder signal that requires less amplification from the phono stage circuitry, so the noise floor is essentially masked to a certain degree by the stronger signal. That said, it is never a bad thing to have the quietest tubes in a phono stage, be they moving coil or moving magnet.

Dan,
Was this tube testing in preparation for your new amps?

Kevin......Yes and no. By that I mean yes, I knew the new amps were on the way and I wanted to ensure the C2300 performance wasn't being held back by weak tubes. The no part of the answer is I normally have an annual schedule for preventative maintenance that I usually perform each year in June. I was lax this year and let June, July, and August slid by without doing my due diligence. This has been a tough year for me. Here it is September already, so the arrival of the MC75's triggered me to get in gear.

When I perform my annual tube testing I keep records of each tube's numbers, i.e. transconductance, gain, and in the case of the small tubes, noise. That way when next year's tests are done I can refer back to the previous year's numbers for reference. I also test and record the information on all new tubes purchased, again as a reference point for testing annually once new tubes are put in service. I also test new tubes to ensure that when I pay for matched tubes they actually are matched. I have found a couple instances where one out of four matched tubes was way off the mark. I buy from reputable tube venders so getting a replacement happens without an issue. Like everything else, some things require specialized tools. Owning tube preamplifiers and tube power amplifiers practically demands that a tube tester be available.

Sub’d.

sub'd also for fun, I have a c 50 but for some reason I'd love to try a 2300.

Thank´s again, maestro.

C2300 Motivation
 

My dealer frequently asks why I don't "upgrade" my 7-8 year old C2300. Besides the extremely quiet operation, multiple balanced inputs that exceed current models, and the ability to upgrade peripheral components around it< I can never see a reason to trade up(?). Besides, my investment in premium XLR cables is substantial!

Still running with my original tubes............your suggestions for a supplier would be appreciated. (Cryo?) My Anniversary twin MC275's need tube swaps too.

Thanks for making me love my C2300 even more.

Bruce.......I'm with you on the love of the C2300 preamplifier. In my opinion the C2300 is a superb analog tube preamplifier. It does everything I want it to do and then some. The operating features never get in the way of the sonic performance, and it sounds so good. I don't see myself parting with my C2300. Your dealer is just trying to feather his own bed with the sales pitches about your "old" preamp.

Tube venders I use are TubeMonger.com, TubeDepot.com, TheTubeStore.com among others. SweetWater.com sells 12AX7 tubes, and so does Amazon.

I’m with both of you, I love my C2300. Never giving it up.

https://m.youtube.com/watch?v=dQw4w9WgXcQ

:D