Let's see your tubes!

driguy · « **Reply #440 on:** 4 May 2013, 07:33 pm »

My just completed 20B/300B amp. The wood is cocobolo on the chassis and spalted maple for the transformer / choke cover. Polished aluminum for the top plate. No electrolytics in the amp except for the tube heater modules. Yup, that includes the cathode bypass cap and all power supply caps. Very clean, open sound with as little impediment in the signal path as I could muster. There is an input step up transformer (Lundahl amorphous core 1:4) to get full gain on the amp. Really no magic here at all except for using the components that IME have given me the best sound over the years.

Tony

FullRangeMan · « **Reply #441 on:** 4 May 2013, 08:39 pm »

Driguy,
Beautiful amp, congratulations for the good job.
How is the sound of this 20B tube??
Thanks

driguy · « **Reply #442 on:** 4 May 2013, 09:13 pm »

The sound is very much like other Emission Labs tubes that I have used (the regular 300B and the XLS). Very clean with very little coloration (that I can sense). If you read some of the online 300B comparisons it seems to be the general consensus on their sound. I used them in my headphone amp that I brought to RMAF last year. I chose them for that reason. I got a little tired of tube rolling to be honest. For me at least, I just want the amp to pass on the music without much editorializing. I realize a lot of tube guys like to roll 'em but I do not. It constantly leaves one with a feeling of "can I get a better pair". I went through that with 6SL7's and 6SN7's in the previous iteration of the amp. When I built the headphone amp with a driver stage I realized just how much the driver tubes took hold of the overall sound. Too much for my liking. I wound up removing the stage for an input tranny instead.
I think a lot of tube guys realize (at least DIY'ers) that some of the sound changes from tube rolling come from tubes not all conforming to standard. Some would be very surprised just how much thngs change (voltages, etc.) when rolling tubes.
That being said, the 20B as a driver has plenty of current to drive the next stage if and when it gets driven to class AB. Some of the clipping in 300B amps comes from insufficient driver stages. Using a 6SL7 is a prime example of this though really good sound can be had in spite of that! Also, the larger tubes allow for a more linear tube than the smaller octals. See the Emission Labs site for more info on that. They also claim that using a driver tube with similar plate curves cancels 2nd order harmonics as well but their source is in German only. I have not tested the amp for that yet. Still in the "I just want to listen to it" stage.
I think that the biggest concerns for potential users are simply cost and an adequate power supply.

Regards, Tony

FullRangeMan · « **Reply #443 on:** 4 May 2013, 09:51 pm »

Thanks you for this detailed reply, I appreciated.
Seemd transformers are very good for input gain stage, but it is very little used.
Regards

FullRangeMan · « **Reply #444 on:** 4 May 2013, 10:17 pm »

Quote from: SET Man on 30 Apr 2013, 11:28 pm

Hey!

Man! The 212E makes 845 look tiny like EL34 How many watts can you get out of the 212E?

Take care,
Buddy

Hi,
May be you would like this new giant monoblock 212E amp from Ming-Da.
Input are 6H30 + 12AX7 for conservative 35W, 60Kg per channel and plenty of VUs:
http://www.mei-xing.com/english/English/cp/2_998-dw.html

Unison845 · « **Reply #445 on:** 5 May 2013, 07:02 am »

Interesting 212 amplifier from China.http://www.mei-xing.com/english/English/cp/2_998-dw.html

I have been testing different driver tube (845) using Shuguang 845, 845B (Amperex replica graphite), 845C (Amperex replica with metal) and GE 845, and the result was :
1st. Shuguang 845B.
2nd. GE 845
3rd. Shuguang 845C
4th. Shuguang 845

The 211 tube can also be used as driver in this amp by a flip of a switch, I hope to be able to get few different 211 to try out.

adrianc · « **Reply #446 on:** 7 May 2013, 07:04 pm »

Philips earliest ECC83 MCA Delta 3.Made in 1953-1954

FullRangeMan · « **Reply #447 on:** 7 May 2013, 08:28 pm »

Quote from: adrianc on 7 May 2013, 07:04 pm

Philips earliest ECC83 MCA Delta 3.Made in 1953-1954

I never would say these are 12AX7 subs with this tall plate.

carusoracer · « **Reply #448 on:** 7 May 2013, 08:29 pm »

Quote from: driguy on 4 May 2013, 07:33 pm

My just completed 20B/300B amp. The wood is cocobolo on the chassis and spalted maple for the transformer / choke cover. Polished aluminum for the top plate. No electrolytics in the amp except for the tube heater modules. Yup, that includes the cathode bypass cap and all power supply caps. Very clean, open sound with as little impediment in the signal path as I could muster. There is an input step up transformer (Lundahl amorphous core 1:4) to get full gain on the amp. Really no magic here at all except for using the components that IME have given me the best sound over the years.

Tony

Very Nice Work Tony

Bob2 · « **Reply #449 on:** 8 May 2013, 11:48 pm »

Driguy, nice looking amp!
Well done!! Hope it sounds as great as it looks!
The cocobolo looks nice!

driguy · « **Reply #450 on:** 10 May 2013, 08:18 am »

Quote from: Bob2 on 8 May 2013, 11:48 pm

Driguy, nice looking amp!
Well done!! Hope it sounds as great as it looks!
The cocobolo looks nice!

Thanks, it does sound great even though I only have about 60 hours on it. The soundstage is really large and the front to back layering is exceptional.

Tony

adrianc · « **Reply #451 on:** 12 May 2013, 04:15 pm »

Philips second generation ECC83,made in Holland but with Valvo printed.
First Ecc83 with foil stripe getter 45 degree on top mica.Date code MCN Delta D,no holes on plates.