OTL Asylum

Tube Rolling an MP1 3.3

75.191.81.63

Simon Templar

MP-1 (Mk3.3)
If I wanted to try some NOS 6SN7's, which would benefit most from the swap?
Are there any positions that would make little or no difference?

.....sT

Edits: 02/21/23

Follow Ups:

MP-1 Mk3.3 most important tube positions. - Ralph 13:10:57 02/22/23 (2)
For the 6SN7s, the one in each channel closest to the front has the most effect. The Linlai is the best we've heard so far. No idea how long they last. The best NOS tube seems to the the KenRad.

For the phono section the 12AT7s nearest the rear panel have the most effect. They should test very high on a tube tester and matched internal sections help! For this reason the Chinese tubes get high marks.

There are 4 12AT7s in a row in the rear of each channel. Its the 3 closest to the rear that are the most important. They all have equal merit as they are paralleled (for lower noise and better ability to drive the 4th tube in that row).
- RE: MP-1 Mk3.3 most important tube positions. - Simon Templar 22:47:09 03/04/23 (1)
  >
  > There are 4 12AT7s in a row in the rear of each channel. Its the 3 closest to the rear that are
  > the most important. They all have equal merit as they are paralleled (for lower noise and
  > better ability to drive the 4th tube in that row).
  >
  
  They are all three in parallel, so does that then mean that (sonically) if one is replaced then they ALL should be identically replaced?
  
  ....sT
  
  Edits: 03/05/23 03/05/23
  - No- what is important is that the tube actually be good and tests strong nt - Ralph 14:55:13 03/07/23 (0)
    -
That's an MA-1 v. 3.3? If so, the 1st-stage Voltage-gain tubes... - jeffreybehr 12:21:40 02/22/23 (1)
...make the most 'sound'.. I don't have a manual for that amp (I have an MA-1/3.1), but the rear two (closest to the transformer cover) 'N7s and one in the 2nd (from the transformer cover) row are all in parallel.. (I expect Ralph will tell us which one is part of that trio.) The least-important tube of the 5 is the single in front, being the impedance-reducing cathode-follower driver.

My goal in reproduced sound, tonally, is natural warmth and bloom and NOT ruler-straight, 'neutral' sound which I find too thin, and my favorite 'N7s are Tung-Sol roundplates and BRIMAR curved plates.. Both are long-discontinued and rather expensive.. Fortunately for me, I 'grew', years ago', a nice batch of each and now have a lifetime supply.

I recommend you read Brent Jesse's page on 'N7s.
- http://www.audiotubes.com/6sn7.htm (Open in New Window)
- OOPS--wrong piece. (NT) - jeffreybehr 12:17:44 02/26/23 (0)
  .

Post a Followup:

FAQ

Post a Message!

Forgot Password?

Moniker (Username):
Password (Optional):
	Remember my Moniker & Password (What's this?) Eat Me
E-Mail (Optional):
Subject:

Message:	(Posts are subject to Content Rules)

Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:	Automagically notify you when someone responds.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.

This post is made possible by the generous support of people like you and our sponsors:

Parts Connexion