Gain drop off

[Systematic Chaos]

Original tubes on my MP-1 were red stamped 12AX7A...100% chinese tubes, no brand on them.
Very good tubes...and I will keep them!

The same tube (but with nothing stamped on it) was in the Zoom 9150 (I will keep it as well).

I agree about TADs...I put there a couple of 7025, as I already wrote...and they sound very, very close to originals.

But I'll try JJs soon...

The TAD 7025 is their modern take on a MilSpec 12AX7 (4-digit numeric number), a slightly "stiffer" engineered 12AX7 for demanding Mil applications back in the day.
I direct comparison it (according to my ears...VanSinn had the same results though when I sent him a TAD 7025 for his MP2 some 8 years ago) sounds stiffer and more high-mid/high prominent (some call it ice-picky) and very very linear (which is good in a "perfect environment" and for the applications the tubes were initially designed for).

I personally couldn´t care less for the "Matched and Balanced" in preamp slots....If you have tubes with lightly different ratings (gain-wise) on each of their triodes you get some awesome odd-stacked harmonics in the gain structure since it´s no perfect linear distortion....

YMMV


SC

[Iperfungus]

The TAD 7025 is their modern take on a MilSpec 12AX7 (4-digit numeric number), a slightly "stiffer" engineered 12AX7 for demanding Mil applications back in the day.
I direct comparison it (according to my ears...VanSinn had the same results though when I sent him a TAD 7025 for his MP2 some 8 years ago) sounds stiffer and more high-mid/high prominent (some call it ice-picky) and very very linear (which is good in a "perfect environment" and for the applications the tubes were initially designed for).

I personally couldn´t care less for the "Matched and Balanced" in preamp slots....If you have tubes with lightly different ratings (gain-wise) on each of their triodes you get some awesome odd-stacked harmonics in the gain structure since it´s no perfect linear distortion....

YMMV


SC

Compared to TAD 12AX7A-C, you mean?
This one?

http://www.banzaimusic.com/TAD-12AX7A-C-ECC83.html

I've this (Highgrade) in V1:

http://www.banzaimusic.com/TAD-7025-S.html

and this in V2:

http://www.banzaimusic.com/TAD-7025-Highgrade.html

I've to try them swapped...

Is one of those the TAD 7025 you're speaking about? Or is this one?

http://www.banzaimusic.com/TAD-7025-E83CC-Highgrade.html

TAD has too many tubes...  :facepalm:

By the way...TAD 12AX7A-C is not expensive...I've to try them...

[Systematic Chaos]

Don´t get fooled by the "Highgrade" description....
Check the description directly on the TAD page....

As I mentioned earlier (and IIRC we came to a common consensus since a lot of folks have tried) the RT001 (12AX7A-C) is the closest (on steroids) you can get to the originals...

Give it a try!

[Iperfungus]

Don´t get fooled by the "Highgrade" description....
Check the description directly on the TAD page....

Yes...I've done that years ago, when I bought those tubes from TAD directly...
Descriptions look the same, more or less... 

BTW, I like those 7025 in my MP-1...

As I mentioned earlier (and IIRC we came to a common consensus since a lot of folks have tried) the RT001 (12AX7A-C) is the closest (on steroids) you can get to the originals...

Give it a try!

I will!!!  :thumb-up:

[Systematic Chaos]

Here´s the thread: http://adadepot.com/index.php?topic=543.msg5921#msg5921

some more: http://adadepot.com/index.php?topic=17.msg5706#msg5706
http://adadepot.com/index.php?topic=17.msg5725#msg5725

and also very important:http://adadepot.com/index.php?topic=17.msg5859#msg5859

[Iperfungus]

Here´s the thread: http://adadepot.com/index.php?topic=543.msg5921#msg5921

some more: http://adadepot.com/index.php?topic=17.msg5706#msg5706
http://adadepot.com/index.php?topic=17.msg5725#msg5725

and also very important:http://adadepot.com/index.php?topic=17.msg5859#msg5859

:thumb-up:

Thanks a lot, SC!

[DannyjoeCarter]

Awesome guys and thanks so much for all the tube info!!!!!

MJMP suggested I speak to Doug at Doug's Tubes and recommended these specifically for the MP-1;

http://www.dougstubes.com/ruby-12ax7-ac7-hg.html

So share your thoughts again guys  :D

Hey DJC,

the ECC83M is a rebranded Chinese 12AX7A (info from Marshall R&D who used the ECC83M around that time as well). The closest (and I mean real close) new tube you can get is the TAD 12AX7A-C (RT001)

The Chinese 12AX7A (Shuguang plant) was widely used in a gazillion of guitar amps/manufacturers in the 80s and went through some revisions (rev A - rev C).
TAD has their tubes built by the Shuguang plant as well but to TAD specs...and for the RT001 they took all the best bits and pieces of the Chinese 12AX7 and "designed" them into one tube which is their best-seller 12AX7A-C. You´ll get the sound of your beloved ECC83M on tiny spoonful of steroids.


SC

And I will give these a spin too SC, thank you!  :D

[rnolan]

I haven't tried the Ruby badged JJs, but I know MJMP likes them allot, like Harley, I'm a fan of long plates as I find them more 3D and articulate (and interesting).  I need to crack open my working (US version  :facepalm: ) MP-1 and try some Mullard LPs in it.

[DannyjoeCarter]

I haven't tried the Ruby badged JJs, but I know MJMP likes them allot, like Harley, I'm a fan of long plates as I find them more 3D and articulate (and interesting).  I need to crack open my working (US version  :facepalm: ) MP-1 and try some Mullard LPs in it.

This long plate/short plate thing is all new to me Richard; could you give me a little break down on this, like tonal variances between them and gain structure if you don't mind  :D

[Systematic Chaos]

Awesome guys and thanks so much for all the tube info!!!!!

MJMP suggested I speak to Doug at Doug's Tubes and recommended these specifically for the MP-1;

http://www.dougstubes.com/ruby-12ax7-ac7-hg.html

So share your thoughts again guys  :D

To be completely honest....this recommendation has me a bit laughing. The Ruby 12AX7 AC7 HG is identical to the TAD 7025S Mullard Reissue. Now that´s a completely different approach than the tube you´re trying to replace (sound-wise).
Also, the TAD Mullard RI sounds nothing like a Mullard...the closest to the orig. Mullard is the New Sensor Mullar RI Longplate.

Seriously, If you wanna replace them ECC83M with their best nowadays available 1:1 get the TAD 12AX7A-C (RT001).
I´d also try and combine a TAD 12AX7A-C in V1 with a Mullard RI Longplate in V2

Just my 2 Yen ;-)

[rnolan]

(I´d also try and combine a TAD 12AX7A-C in V1 with a Mullard RI Longplate in V2) a very good suggestion SC  :thumb-up: . I have some spare Mullard LPs, I bought 6 last purchase  >:D , I'll get some TADs to try a bit of mix and match.  Mike has the RI Mullard short plate in V1 and SPAX7 in V2 IN HIS mp-1, that combination also works well.

@DjC, it's all very subjective this stuff, also the differences can be quite subtle.  In the end you just have to try a few options and make your own mind up what works best for your unit and playing style.  My experiences are with the MP-2 which is a very different beast to the MP-1. None of the tubes suggested here will be terrible, just a bit different (some more than others). Compared to the original tubes and then Boogie SPAX7s (JJs), I found the New Sensor Mullard RIs to have more depth, nice and smooth and more 3 dimensional and more articulate (they seem to track even the slightest variation in left hand fretting pressure (this took me by surprise)).

[Iperfungus]

I haven't tried the Ruby badged JJs

I'm about to do that...  :banana-rock:

[Iperfungus]

The Ruby 12AX7 AC7 HG is identical to the TAD 7025S Mullard Reissue.

Not a bad tube at all...  :thumb-up:

[DannyjoeCarter]

This is interesting stuff for sure guys and what I was hoping to hear from all of you.
So it seems the TAD 12AX7A-C that Systematic Chaos suggested and a few others is probably going to be the way to go so I will give that a shot. With the money we have already spent on all the gear in the last two months a few bucks on preamp tubes will be a drop in the bucket.

And yes Richard I agree 100% about it all being subjective; whats amazing me too is how different the batch of 10 original red letter ECC83Ms Jason and I have acquired sound!  Of coarse how much these tubes were played has lots to do with it but some of these are night and day. And even changing the same tubes from positions one and two sound different! ???

[Iperfungus]

And yes Richard I agree 100% about it all being subjective; whats amazing me too is how different the batch of 10 original red letter ECC83Ms Jason and I have acquired sound!  Of coarse how much these tubes were played has lots to do with it but some of these are night and day. And even changing the same tubes from positions one and two sound different! ???

That's tubes rolling fun!  :banana: