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6EM7 power amp
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Author:  Sound Barrier [ 16 Sep 2013, 02:37 ]
Post subject:  Re: 6EM7 power amp

Mark, you mentioned the Arabella did not have quite the depth or clarity of the Paris. By depth do you mean soundstage depth?
Also has it improved with further run in? How does it go involvement- wise against your previous amps?

Author:  mwhouston [ 16 Sep 2013, 05:26 ]
Post subject:  Re: 6EM7 power amp

Sound Barrier wrote:
Mark, you mentioned the Arabella did not have quite the depth or clarity of the Paris. By depth do you mean soundstage depth?
Also has it improved with further run in? How does it go involvement- wise against your previous amps?

Arabella got a lot better after about 10 hours. Initially it was ordinary then it really hit its stride. Soundstage is deep and (in most orchestral) speakers disappear. As I may have explained it treats all music with a light tought. No heavy harmonics or super lush mids. Clear, clean and relaxed. But I think Paris may hold the upper hand but at a price for all out performance. Paris was easily 50% more expensive and is a true integrated. Arabella has better OPTs. Though I loved Paris to death and would be happy with either if a gun was held to my head and forced to choose-Arabella. It sounds even more open and simpler.

Author:  mwhouston [ 16 Sep 2013, 21:05 ]
Post subject:  Re: 6EM7 power amp

I have been asked to take Arabella to a friend's (Russell's) house who also bought my C3m preamp (Menatzchim) and the first of the SE UL EL34 amps (retro34UL). We were discussing power and speaker impedance and I mentioned I thought Arabella would have put out more than 1.8W.

Then Russell pointed out that I tested Arabella on an 8.2ohm resistor and the OPTS are rated for 6ohms. Therefore probably if I tested Arabella on a 5.6ohm load I may have seen a higher power output. I reckon Russell is right. I feel better now. We will see how well Arabela goes driving Russell's big KEFS tomorrow.

Author:  mwhouston [ 18 Sep 2013, 08:25 ]
Post subject:  Re: 6EM7 power amp

Russell purchased Arabella today after a number of AB comparisons with the EL34 amp. Once more I was impressed with how well this amp drove the big KEF boxes. Also I was impressed how good the KEFs sounded.

For me I would be happy with either amp both sound excellent. The retro34UL amp had a more lush mid range where Arabella was a little dryer and clearer in the mids. It would probably all get down to personal taste.

Author:  Suncalc [ 18 Sep 2013, 18:45 ]
Post subject:  Re: 6EM7 power amp

mwhouston wrote:
Russell purchased Arabella today after a number of AB comparisons with the EL34 amp.
Mark;

I seem to have noticed that you have a problem holding on to these little amps. They must be bloody good. It is safe to assume that Arabella was not your last 6EM7 build?

Author:  mwhouston [ 19 Sep 2013, 08:49 ]
Post subject:  Re: 6EM7 power amp

Suncalc wrote:
mwhouston wrote:
Russell purchased Arabella today after a number of AB comparisons with the EL34 amp.
Mark;

I seem to have noticed that you have a problem holding on to these little amps. They must be bloody good. It is safe to assume that Arabella was not your last 6EM7 build?

Well I have sad news. Like an old lover, it's time to let go and move on. I have thought about this the whole day. To help decide Russell is going to take all my last 6EM7 tubes. And some nice ones at that.

Ahead: my twists on Matt's 6V6, another EL34 amp, 6C33C and 211 amp. All of which I have power trannies and\of OPTs plus many other required parts.

Matt may I please ask you to come up with a 211 design. I'll make a deal with you. Start a thread, progress us through the design proceedure and I will start building ahead of the other projects. My 211s (Chinese made) I have had for years plus thier ceramic gold plated sockets. I have thier Edcor OPTs and a toroid tranni custome wound for 1200V. Images of the 211 to follow.

Matt, do we have a deal?

Author:  mwhouston [ 19 Sep 2013, 19:00 ]
Post subject:  Re: 6EM7 power amp

I know it is off thread but I promised an image of my Chinese made 211s. If anyone recognizes the manufacturer please let me know. I have had them for many years and they may be early Shuguang. The box they came in is plain cardboard. Sorry no more off thread.
Attachment:
211Tube.jpg

Author:  Geek [ 20 Sep 2013, 04:14 ]
Post subject:  Re: 6EM7 power amp

Looks like a generic Shuguang to me.

Author:  mwhouston [ 20 Sep 2013, 08:55 ]
Post subject:  Re: 6EM7 power amp

Geek wrote:
Looks like a generic Shuguang to me.

Geek: I'm with you. Is there anyway I can prove this? I'll take a look at the tubes they have on offer to see if I can spot a similar tube.

I did find this. Looks familiar. http://www.ebay.com/itm/Pair-Matched-Shuguang-211-Vacuum-Tubes-/221180322510?pt=Vintage_Electronics_R2&hash=item337f5fe2ce

Author:  Geek [ 20 Sep 2013, 20:17 ]
Post subject:  Re: 6EM7 power amp

Those are later Shuguang.

Yours looks late 80's to early 90's.

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