Is Doc a Saint or .... ??

[ALL212]

You will  get more out of swapping to a high grade balanced HP cable than changing the shunt regulator tube. Hell, the interconnect qualities are easily revealed by this amp.

IMHO, its just fine. The only thing left to do is to pick your colouration of choice. Changes are likely to be minute but with a high expense. Those changes may be  thought to be towards improvement, but the reality is they are small enough generally you could con yourself in into endless circles.

Mine's here!!  Much work to do before assembly but...

I've already got my own HP cable, will going from 1/4" to the XLR improve things?  Can Senn HD 650's use an XLR?  I can make the cable, that's not the problem.  I'm just not familiar with the XLR and any advantage it may have.

[NightFlight]

XLR would seem to make a difference to me. I decided to go with Moon Audio rather than possibly be disappointed with a first time DIY project.  It could be the cable is imparting some of the improvement over stock.  Actually I have no doubt that is the case. As for XLR/Balanced. For me, I've gone back the single ended a couple times for testing something, but so far its never stayed that way. YMMV.

The 650 can be balanced very easily. The connectors are common and easily soldered. See ebay for a world pre-fab ones.

[ALL212]

It's in - and here's a start.

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi905.photobucket.com%2Falbums%2Fac253%2Fall212212%2FDSC_4248_zps6rbxbiea.jpg&hash=ce22e7ee7355f2e4955ec5aea70c3f903c9fdd76)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi905.photobucket.com%2Falbums%2Fac253%2Fall212212%2FDSC_4246_zpsr5xlfpxl.jpg&hash=6a82df7702e58e135ec31403cbc80122bab71c8d)

[JamieMcC]

It's in - and here's a start.

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi905.photobucket.com%2Falbums%2Fac253%2Fall212212%2FDSC_4248_zps6rbxbiea.jpg&hash=ce22e7ee7355f2e4955ec5aea70c3f903c9fdd76)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi905.photobucket.com%2Falbums%2Fac253%2Fall212212%2FDSC_4246_zpsr5xlfpxl.jpg&hash=6a82df7702e58e135ec31403cbc80122bab71c8d)

 I was just thinking the other day its been a while since there have been some new Mainline build pics enjoy the build. 

[ALL212]

Update:

Final output cap is 3x 30uf Solen film caps.  Couldn't find room for a 100uf.  These three measure closer to 100uf than the stock cap did.

Choke in place of the 270 ohm resistor.

Mogami wire will be used as much as possible.

Sound damping material on the plate - takes some boing out.

Voltage checks on the PS went just fine.  So far...so good.

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi905.photobucket.com%2Falbums%2Fac253%2Fall212212%2FDSC_4510_zpsjspzhhxj.jpg&hash=932b1b3e6c13778cc0916a74530c682d54efbdea)

[Strikkflypilot]

Looks stunning so far!

[JamieMcC]

Is the choke you used in place of the 270 ohm resistor the Triad C7X I have a couple in my parts box and was wondering?

[mcandmar]

Very tidy build. I hope i am wrong about this, but i don't like the look of that choke so close to the output transformer.  It may work fine, but i wouldn't be surprised if it created a lot of noise on that channel..

[ALL212]

Is the choke you used in place of the 270 ohm resistor the Triad C7X I have a couple in my parts box and was wondering?

Yes, it is - and it is an experiment.  If I get some noise it should be an easy thing to just pull it and put the resistor back in.  That's one of the reason's I decided to try it - easy access.

And I'm on temporary hold.  One of the volume switches is missing one bottom lug so that's on the way back to BH land so I can get a new one.

[Paul Birkeland]

Very tidy build. I hope i am wrong about this, but i don't like the look of that choke so close to the output transformer.  It may work fine, but i wouldn't be surprised if it created a lot of noise on that channel..

Its core is oriented at 90 degrees to the output transformer, which should be helpful in terms of noise mitigation.  This is hypothetically a much better place to put the choke compared to mounting it above one of the output transformers.

[ALL212]

Starting the fine and course volume control soldering really needs a warning label:

NO COFFEE!!!

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi905.photobucket.com%2Falbums%2Fac253%2Fall212212%2FDSC_4539_zpsq6wcdstw.jpg&hash=3cc9f9dc1af3dba2c549a669491909f7ab5a92ad)

[Rocketman248]

Very clean build!  Can't wait to start building mine.   

[ALL212]

Impedance switching is complete.

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi905.photobucket.com%2Falbums%2Fac253%2Fall212212%2FDSC_4552_zpshoyiyj8b.jpg&hash=5eb3cf2dcd8bb8b98235b4202379aacef61df74c)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi905.photobucket.com%2Falbums%2Fac253%2Fall212212%2FDSC_4554_zps3sxvcuxx.jpg&hash=1dc80ce9698c8f0239a15882cdcdd6d258e912c4)

[Paul Joppa]

Actually, the coil axis of the choke is the same as the output transformer, so there may be some hum coupling. Not easy to predict the magnitude though.

You can listen to the speaker to determine whether the noise is acceptable, and whether it is noticeably different from the other channel.

[ALL212]

I have some aluminum tape - if I wrap the choke in that do you think it would do anything at all?