New Tubes Advice

[rnolan]

Sounds like a good combination 

[vansinn]

I too use a TAD, though it's the RT001 (IIRC), as v1 in my MP-2, and a NOS Philips ECC83 in v2 pos.
The RT001 is a bit edgy and serves to brighten the pre-gain tone, while the Philips is more full-bodied and serves to round-off as a finalizer.
I would probably choose a Mullard reissue as v2 if/when the Philips goes to vacuum heaven.


Dad, what is the mind?
- What's the matter?  Well, never mind..
-- Homer

[Syntho]

I'm about to repair my MP1 and I want to change the tubes. There are 13 pages here and I read through most of it but I'm not sure this question has been asked yet: is there a consensus on which tubes to get to match what the original MP1 was like? My MP1 is an early version, no mods, and I'm not looking to get ultra brutal high gain either. I want it pretty much stock sounding. Which tubes do you recommend? Maybe just some regular JJs?

[rnolan]

Hey Syntho, SC recons the TADs are as close to stock as he's heard.  When I had my original MP1 (new) I eventually put some Boogie STRs in it (pretty much JJs rebadged as Boogie).  I liked them in the MP1, not so much in my MP2s.  I have a couple of MP1s that are with my tech trying to get at least 1 working.  It's having midi program select issues but otherwise it works.  It had some GTs in it which sound very edgy so we put in a pair of Mullard long plates (same as I use in all my MP2s), made it sound heaps better, my tech was blown away how much difference it made.

Based on input from SC, it seems the closest modern tube to the original Chinese bottles are the TADs, so worth a try if you want the original stock sound, (which is awesome  )

[Syntho]

Looks like I missed that info, it was the last post on the first page :)

So it looks like TAD 12AX7A-C tubes are my best bet. I've already got some TADs in another tube amp and they're rock solid. Think I'll pick up a couple of them.

When I buy power amp tubes I make sure they match, but for preamp tubes, does it matter if they're matched?

[vansinn]

Not sure the TAD's are the best solution for tube #2.
I've tried several combinations in my MP2; a TAD 001 in pos #1 and a Philips NOS ECC83 (12ax7) in pos #2 works very well.
The TAD has a bit edgy bite and cuts through nice, whereas the Philips is slightly rounding-off - the same would result using a long-plate in pos #2. albeit lilely with a slightly darker sound..

I never fully liked the tone off JJ GoldPin high-gain tubes, too rounded off at the high end. However, just might work well in pos #1 with an open-sounding, hi-fi-like, tube in pos #2.

In essence, I'd recommend a TAD RT001 in pos #1 and a [Mullard] long-plate in pos #2.

Can't comment on tubes for MP1; I never changed stock tubes in the one I had mid/late 80's.

[rnolan]

Hey Syntho, Vans suggestion would also work in MP1.  No they don't have to be matched for guitar pre amp (e.g. MP1/2).  In a tube stereo power amp it makes sense to match tubes across the 2 channels (input/buffer tubes and output tubes) so both channels perform the same.  In the MP1 one tube comes after the other building gain and they don't have to be the same.  In Vans suggestion (TAD in V1 and Mullard long plate in V2) the Mullard will give the TAD some nice depth (3D ness) and the TAD will set the basic tone.

[Chip Roberts]

I just replaced the EHXs in one of my MP1s with a pair of TAD 12AX7As, but after a few weeks I don't think they're doing it for me.  The TADs are a bit too warm, even a bit whoofy for my taste.  My other MP1 had JJs in it, which sound nice and cutting with a good tight low end.  I have a couple of other options I'm looking at based off a few threads here.  Let me know what you folks suggest.

Sovtek 12AX7WB
Sovtek 12AX7-LPS
Boogie SPAX7s 

[rnolan]

The boogie tubes are often JJs (not always though) but they work well in MP-1 albeit they are twice the price (here in Oz), don't know about the Sovteks, I think some love them some don't, I like the Mullards (no surprise there) they have a long plate and a short plate version.

[Chip Roberts]

I have a spare that I bought since I had thought one of them crapped out in my Rockmaster.  I imagine it's probably going to cost quite a bit more to ship things from the US to Oz, though I'll be ordering a kit from PitBull Guitars in the next few months, so I'm sure I'll be on the receiving end of that deal soon enough  ;)

I have a whole bunch of GTs that I've taken in and out of various preamps over the years in a baggie, so maybe I'll roll some of those in and out just for the hell of it.  Do you recommend the Boogie in V1 or V2?

[rnolan]

Hey Chip, one of the reasons I went with the boogie SPAX7s was I can buy them from the local store as they are boogie distributors, I got a reasonable discount but the full retail here  is $50+ AUD, everything boogie is exe...When I used MP-1 I put SPAX7s in both V1 and V2.  My friend MikeB has it these days and he has SPAX7 in V1 and Mullard short plate in V2.  More recently I bought a couple of MP-1s which I'm still trying to get working.  I swapped the tubes in the "working" unit (midi still isn't working properly but the unit works fine apart from that), I put 2 Mullard long plates in it and it sounded sooo much better, I think I pulled out GTs or maybe they were EH ?  I don't like either much. I have GTs in my Carvin TS100 and they are fine in that context, being a clean and transparent power amp (rated for using to power studio monitors).