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PostPosted: Thu Aug 02, 2018 5:12 pm 
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Location: Calgary, AB, CA
The shipping is worth more than the parts, but at least they are available.
Gary has been very accommodating as usual. Its nice to get that kind of after sales service.

:D Absolutely Im going to keep C6,C6A complete with cascade bypass. Might bump the bias resistor up to 10k.
It would be nice if the vc worked from 10>2 rather than 8>10.


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PostPosted: Thu Aug 02, 2018 6:15 pm 
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Joined: Tue Jul 12, 2011 7:34 am
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Location: Edmonton, AB, CA
Maybe change the VC value? Off hand I don't recall the stock value but 50K (47K) is pretty common. Sometimes the taper is wrong or the value is too high. I have a box of Blue Alps 50K pots for just this occasion. :)

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PostPosted: Thu Aug 02, 2018 7:56 pm 
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Location: Calgary, AB, CA
The pot in my rebuild is 100k. Probably the taper would have more impact?


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PostPosted: Tue Aug 07, 2018 4:55 pm 
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Joined: Sun Sep 23, 2007 11:55 am
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Location: Calgary, AB, CA
Im almost wishing I would have kept this 301. LOL

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Gold plated tube sockets, Amtrans film caps, Nichicon KXM PSU caps, TDK Epcos, and Rubycon bias bypass caps, Wurth Elektronik, custom bias point, custom discrete diode bridge, oversized Hammond choke, full cascade bypass on C6/A,C8/A


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PostPosted: Wed Aug 08, 2018 10:03 am 
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Joined: Thu Jan 26, 2012 10:34 am
Posts: 336
Location: Ardrosssan, AB, CA
That looks like an awesome start to the new build!


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PostPosted: Wed Aug 08, 2018 10:40 am 
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Location: Edmonton, AB, CA
Bruce,

It looks fantastic! You've really outdone yourself this time. :D

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Last edited by petersch on Wed Aug 08, 2018 1:39 pm, edited 1 time in total.

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PostPosted: Wed Aug 08, 2018 12:10 pm 
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Location: Calgary, AB, CA
Im waiting for the last of the parts then I can do the final assembly. I am pretty curious as to how this version is going to sound :D
Thanks for the kind comments.


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PostPosted: Sun Aug 12, 2018 4:26 pm 
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Location: Calgary, AB, CA
I am really happy with the sound of the rebuilt 301. It seems to have worked out very well. I made the choice of not increasing power supply capacitance by much but concentrated on using really good quality PS caps. Also I think the Amtrans coupling caps have turned out to be much better than expected.
There isnt much that can be done with the power supply in the 301, but the discrete diode bridge and the oversized choke, seem to be a really worthwhile upgrade. The inductance goes from 1H to 1.5H
I implemented the change in my own 301, after hearing the rebuilt version.
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PostPosted: Sun Aug 12, 2018 5:45 pm 
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Joined: Thu Dec 14, 2017 6:04 pm
Posts: 11
Location: Okanagan falls, BC, CA
Brooster wrote:
I am really happy with the sound of the rebuilt 301. It seems to have worked out very well. I made the choice of not increasing power supply capacitance by much but concentrated on using really good quality PS caps. Also I think the Amtrans coupling caps have turned out to be much better than expected.
There isnt much that can be done with the power supply in the 301, but the discrete diode bridge and the oversized choke, seem to be a really worthwhile upgrade. The inductance goes from 1H to 1.5H
I implemented the change in my own 301, after hearing the rebuilt version.
Attachment:
IMG_20180812_171742734.jpg


Looks great...

-- 13 Aug 2018 01:45 --

Brooster wrote:
I am really happy with the sound of the rebuilt 301. It seems to have worked out very well. I made the choice of not increasing power supply capacitance by much but concentrated on using really good quality PS caps. Also I think the Amtrans coupling caps have turned out to be much better than expected.
There isnt much that can be done with the power supply in the 301, but the discrete diode bridge and the oversized choke, seem to be a really worthwhile upgrade. The inductance goes from 1H to 1.5H
I implemented the change in my own 301, after hearing the rebuilt version.
Attachment:
IMG_20180812_171742734.jpg


Looks great...


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PostPosted: Wed Aug 15, 2018 10:20 am 
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Posts: 105
Location: Calgary, AB, CA
Ronbo7.........thank you.

The rebuilt 301 running a pair of 60's vintage 6J7's and 7581A's. Probably the best sound I've heard from a 301. The 6J7's were just for fun but ended up sounding really clean.
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PostPosted: Wed Aug 15, 2018 1:07 pm 
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Posts: 336
Location: Ardrosssan, AB, CA
Brooster wrote:
Ronbo7.........thank you.

The rebuilt 301 running a pair of 60's vintage 6J7's and 7581A's. Probably the best sound I've heard from a 301. The 6J7's were just for fun but ended up sounding really clean.


Looks great!

6J7, very interesting, not familiar with this tube. How close is it to a 6SJ7? I can see an adapter is needed but wondering more about any sound differences.

Are the 7581A modern day Tung-sol or vintage?

I am curious to hear the difference between the stock tubes and what you are running now.


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PostPosted: Wed Aug 15, 2018 2:18 pm 
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Location: Calgary, AB, CA
The 6J7 was a precursor to the 6SJ7. Very similar tube but the pinout is different. I really like the sound of the 6J7 compared to the pair of 6SJ7's that I have on hand. Considerably better tube all around.
The 7581A is the Tungsol reissue. As other people have mentioned on this thread they are a really excellent match for the 301. ie if you dont have a pair you really should get some :D
The stock output tubes are bearable but the stock driver tubes not so much.


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PostPosted: Sun Sep 02, 2018 9:36 am 
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Location: Calgary, AB, CA
+1


for the reissue Tung-Sol 7581A Tubes! They're awesome! :D :mrgreen: :D


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PostPosted: Fri Sep 07, 2018 9:55 am 
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Location: Chicago, IL, US
Is it possible to use 6SL7 with an adapter in this amp? What, if any mods would be required/is it worth it?


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PostPosted: Fri Sep 07, 2018 12:31 pm 
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Location: Edmonton, AB, CA
pingpongcomputer wrote:
Is it possible to use 6SL7 with an adapter in this amp? What, if any mods would be required/is it worth it?

The 6SL7 is an 8 pin octal so it will fit without an adaptor.
But... 6SL7 is a dual triode, where this amp requires a pentode.
Short answer, won't work, no benefit to making it try to work.


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