ADA Depot - A Forum To Support Users of ADA Amplification Gear

Let's Get Technical => All Things Tube => Tubes (preamp/Input/Buffer) => Topic started by: rnolan on July 26, 2014, 09:05:55 AM

Title: Place to discuss input/preamp tubes
Post by: rnolan on July 26, 2014, 09:05:55 AM
And again, (and probably a more hot topic) preamp tubes (12A??s).  My fave (no secret) are Mullard 12AX7s, I've been using the long plates.  I've got a soft spot for JJs particularly for MP1, the Mullards are better in MP2 IMHO.
Title: Re: Place to discuss input/preamp tubes
Post by: robertkoa on August 02, 2014, 01:45:19 AM
My MP1  came with 2 JJ 83s tubes  and has a  nice clear sound (I don't  like buzzy, fuzzy distortion ).

But I am wondering if a JJ  803s  the longplate might be even smoother /clearer .

On my Hughes @Kettner Tubeman the  JJ 803s  was much more clear.

Anyone tried them in the  MP1 ?V
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on August 03, 2014, 06:17:04 AM
Haven't tried them myself but others here may have ?  I used the Boogie STRs in my MP1 (most likely re-badged JJs but not sure which version, short plates though IIRC).
Longplates are a little more prone to microphonics compared to short plates but I don't think that would be a big issue for your MP1 (depending where you mount it e.g. on top of loud speaker box = more vibration).  MJMP advises not to put long plates in 3TM (but that's super high gain (3 tubes...)) and makes sense.
Personally, I'd try the Mullard long plates (http://www.dougstubes.com/preamp-tubes/12ax7-ecc83-7025/mullard-12ax7.html), I use them in both my MP2s, great tube, very 3D, very smooth.  They also do a short plate model Mullard (http://www.dougstubes.com/preamp-tubes/12ax7-ecc83-7025/mullard-cv4004-12ax7.html) that one of the guys here tried in his MP1 (and liked allot).  Also from the old Depot board, a member tried them (also MP1, long plates), a he loved them.

Anyway let us know how you go, I'm sure the JJ 803s will sound fine.
Title: Re: Place to discuss input/preamp tubes
Post by: trader144 on September 06, 2014, 10:49:08 AM
fWIW, I have a pair of Rubys and they do not sound as good as I had hoped, I read that the preamp tubes do not need to be matched, only the power amp tubes need I be matched. In fact one of the guys who is all digital pedal boards claimed the recorded sound was too digital sounding when mixing for internet broadcasts, but other people liked the same sound when it was live (ouch for an Mp1 guy but so many things change the sound)

In addition to the recommendations here, most of the reviews I have read elsewhere have said very positive things about the mullard reissues except on the jobonamosa group. One of the senior members on the Marshall.com group said he uses a mullard in his YJM100.

I have also been told that the mullard reissue long plates are the 12ax7 and the mullard reissue shortplates are CV4004.

I will post my experience once my mullard long plates arrive.
Title: Re: Place to discuss input/preamp tubes
Post by: rickeb1 on September 18, 2014, 10:24:04 AM
I have an MP-1 with the 3TM mod, and I am really happy using the long plate Sovtek 12AX7-LPS tubes.  They replaced a set of JJs that were good, but these LPS sounded thicker and richer to me, so I kept them in!

I just received an MP-2 (discussed more in another thread).  When I ran through some of the presets when I got it, I was very disappointed in the high gain tones, as they were not very high gain at all, and anything other than clean tones just didn't sound that good.  I opened it up and found 2 Groove Tube 12AX7-R tubes.  I replaced them with the JJs I mentioned above, and it sounded *way* better, so tubes definitely make a difference!  I'm planning on trying the LPS in the MP-2 as well, and I'm definitely tempted to try the reissue Mullards based on rnolan's unwavering endorsement!  :)
Title: Re: Place to discuss input/preamp tubes
Post by: rickeb1 on September 20, 2014, 09:49:34 AM
Just a quick follow-up.  I put a pair of Sovtek 12AX7-LPS in the MP-2, and the thick, rich high gain just brought a smile to my face!  I still plan to try the long plate Mullards because rnolan knows what he is talking about.  :)  But for now, I'm really happy with the LPS!
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on September 20, 2014, 10:12:43 PM
Glad you like the Sovteks in the MP2  :thumb-up: , audophile mate of mine loves them also albeit he wants crystal clean and no distortion in his hifi preamp.
The Mullard long plates seem hard to get at the moment, I hope they aren't caught up in the Russian sanctions... When I first put the in my MP2 I was amazed at how good they sounded, I was swapping out some new Boogie STRs, also a nice tube but not quite as good, particularly for the way I play.
Title: Re: Place to discuss input/preamp tubes
Post by: Systematic Chaos on September 21, 2014, 10:07:45 PM
Just a quick follow-up.  I put a pair of Sovtek 12AX7-LPS in the MP-2, and the thick, rich high gain just brought a smile to my face!  I still plan to try the long plate Mullards because rnolan knows what he is talking about.  :)  But for now, I'm really happy with the LPS!
That's very interesting....I always found the 12AX7LPS too "boring" sounding in preamp stages. Imho it lacks the detail and harmonic content of e.g. the Mullards (reissues)...
However, in the poweramp PI slot the Sovtek 12AX7LPS is magic.....
Title: Re: Place to discuss input/preamp tubes
Post by: El Chiguete on September 22, 2014, 04:53:09 PM
However, in the poweramp PI slot the Sovtek 12AX7LPS is magic.....

What, where, when???  :???: jeje

Kidding aside can you explain this? Are you talking about an MP-1 or another amp/preamp?
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on September 24, 2014, 12:35:19 AM
Hey El, SCs talking about the 1st input tube(s) in a poweramp which typically you want to be clean and transparent and not add colour. My mate (mentioned previously) likes them in his HiFi preamp for the line input stage (CD player, AM/FM Radio, cassette player etc).  I think he has other preferences for the phono input (as it needs to add gain), he's still very much into vinyl records etc as they do sound so much better than CDs if you have the right equipment and good pressings.
Title: Re: Place to discuss input/preamp tubes
Post by: rabidgerry on September 24, 2014, 12:40:30 AM
I asked a stupid question about valves in the tech area which was silly.  This is very useful right here.  I will read the article whilst I do nothing in work today (for all those whom like the bananas)  :banana-trip:

thanks rnolan
Title: Re: Place to discuss input/preamp tubes
Post by: rabidgerry on September 24, 2014, 02:14:21 AM
is there any tube specific to a position in the mp1?  For example do people think one tube sounds better in postion 1 than say position 2?  Or do you all find matched pairs are best?

Forgive my new personness
Title: Re: Place to discuss input/preamp tubes
Post by: trader144 on September 24, 2014, 04:46:25 AM
Yes each position is different as is each tube,
and it depends on your taste.
Ultimately you will have to try both on your own, but V1 is for harder drive than V2.

I have read that matching is only important for power tubes not preamp tubes (mp1 is a preamp)
Makes sense as noted above. I have different tubes in my mp-1 right now.

If you search the site for "mullard" you will find lots of recent tube discussions
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on September 25, 2014, 05:22:12 AM
Hey rabidgerry, trader144  is correct, matched pairs (see elsewhere hear or on Dougs tubes for definition of matched etc) are more important in a tube poweramp that's running push/pull (class B) as each tube does one half of the signal/wave (think sine wave, one tube does top +ve, other does bottom -ve, bias gets set where one takes over from the other). So you want them to be matched for same output.
In MP1/2 preamps, each tube gives you 2 stages of gain (twin triode) so in MP1/2 4 gain stages, 3TM 6 gain stages as the signal is fed progressively through each tube gathering gain on the way (depending on settings, e.g. EL sometimes run his V2 at 0).  So selecting different tubes for V1 and V2 makes a difference and some experiment with various tubes in either position to get the sound they want.  Some try a lower gain tube like 12AT7s instead of the higher gain 12AX7s.
I've always kept it simple and use a pair of the same 12AX7s, previously Boogie STRs (jjs) and now Mullard long plates.  You can play around (tube rolling) but at a cost and probably end up with a drawer full of tubes you don't want.  From another post you said your were thinking about the Mullard short plates (http://www.dougstubes.com/preamp-tubes/12ax7-ecc83-7025/mullard-cv4004-12ax7.html), my recommendation (for what it's worth) is put a pair of these babys in and enjoy  >:D
Title: Re: Place to discuss input/preamp tubes
Post by: Systematic Chaos on September 25, 2014, 11:22:27 PM
Hey El, SCs talking about the 1st input tube(s) in a poweramp which typically you want to be clean and transparent and not add colour. My mate (mentioned previously) likes them in his HiFi preamp for the line input stage (CD player, AM/FM Radio, cassette player etc).  I think he has other preferences for the phono input (as it needs to add gain), he's still very much into vinyl records etc as they do sound so much better than CDs if you have the right equipment and good pressings.
...not entirely correct with the PI being the 1st input tube in the power amp stage....
Here´s a nice and very in-depth article about the importance of the PI slot (and the tubes that go in there...):

The most important tube in your amp? The Phase inverter!
Many people think that V1 (the first gain stage) is the most important tube in an amp. This is true in some cases but not in all cases. V1 (usually the preamp tube closest to the input jack) has the largest impact on your tone and gain but has less impact on your output distortion touch dynamics and output stage distortion than the phase inverter. The phase inverter is generally the preamp tube that is the most close to your output tubes in most amps.
Let’s think about this for a moment. Today’s amps come in many “flavors”. There are three basic amp topologies looking at things from one viewpoint.
• Non Master volume amplifiers
• Master volume amplifiers
• Channel switching amplifiers
In master volume amps we have pre and post phase inverter master volume controls. These work differently but for this piece of writing I will put them in the same master volume category. Rolling down the master does what? It allows the front end to be driven harder and thus we hear our front end distort. At some point we can drive some amps so hard in the front end that the tone becomes so compressed and distorted that even I can sound like a decent player! Your mistakes are covered up in the mush and distortion of ti all. This distortion is passed down the signal chain where it is reproduced and amplified by the output stage of the amp. This has nothing to do with output stage distortion. This type of distortion is not touch sensitive. This type of distortion is not something that most articulate players would favor for a sweet tone, blues tone, or even classic rock tones. This is NOT what people refer to as the “brown sound”.
Channel switching amps. Many of these amps have so much “junk” in the signal path that hearing tube changes in V1 is a pretty hopeless endeavor. When you do hear a change it is because the tube is closer to industry spec than another tube may have been. If you want to hear different great tones from swapping out V1 then listen to the tube under test in a more classic amp design.
Channel switchers continued. I get calls and letters all the time where people have a “bonzo-3 channel gripmaster Mk III recto” or whatever. Many owners of these amps say: “the owner’s manual says that V3 is used for the turbo channel” or whatever. Remember, V1 feeds EVERYTHING else down the line, EVEN IN THESE AMPS. The “turbo channel” generally does not use JUST V3. The chain is fed by V1. V1, even in multi channel amps is still the most important tube in the TONE AND GAIN stage of most amps. If you want to change the ratio of preamp tube distortion to output tube distortion then we change V1 in some cases. Going from a 12AX7 to a 5751 will reduce front end gain. Going down to a 12AY7 will reduce the front end gain further and generally give one more clean headroom.
Back to the phase inverter. Taking a simple classis non-master volume amp (but this is the same for master volume amps as well actually).
I will try to keep things simple here with a few basics. If you have questions on all the complex versions feel free to contact me.
Fender Tolex era amps – These generally used a 12AT7 in the phase inverter.
Marshall type amps – These generally used a 12AX7 in the phase inverter.
There are many other differences in these amps but I will stick to the PI (phase inverter).
Some basic tube facts
• 12AX7
o Has a published spec gain of 100
o Has a publishes spec current output of 1.2 milliamps
• 12AT7
o Has a published spec gain of 60-70
o Has a published spec current output of 10.0 milliamps (ten times that of the 12AX7
as a side note)
As a third example, a 5751 has a gain which is almost identical to the 12AT7 but it’s standing current is 1.0 milliamps (about the same as the 12AX7). But, there is a third factor, transconductance, to be considered. The 5751 has a transconductance of about 1200. A 12AX7 has a “TC” of about 1600 and a 12AT7 has a TC over 5000. These three tubes act quite differently. A 5751 and 12AX7 are much more closely related than the 5751 and 12AT7.
We will stick to the basic 12AX7 and 12AT7.
When you push your amp hard it is not as much the output tubes distorting as it is the phase inverter breaking down and distorting. We are talking output stage distortion here. We are not talking about how you may have messed up the signal with preamp tube distortion and compression already. The phase inverter may be the hardest worked tube in most amps. I cannot begin to count the times when I have found phase inverters that were long past their service life. When you change your output tubes change that phase inverter. At the least change it every other output tube change.
Many folks think that when they want to have their amp have more clean headroom they can insert a 12AT7 in place of the 12AX7. Very true. (By the way, the 12AT7 in a first gain stage is an awful tone generator in a guitar amp. If you want to drop front end gain use a 5751 (gain of 60-70) or a 12AY7 (gain of 40). The 12AY7 was the first gain stage in the classic Fender Tweed Bassman, Deluxe, etc.
Going from a 12AX7 to a 12AT7 in the PI (phase inverter) will yield a change in output tube distortion, touch, and output dynamics in most amps. Is this because the gain is lower in the 12AT7? 10% yes perhaps. The lower gain is a factor but the larger factors are:
• We have almost 10 times the current available to drive the output tubes before the phase inverter starts to break down.
• We have a transconductance of 5500 vs 1600 of the 12AX7. Keeping this simple, it means it takes a lot less input signal for a given output signal.
The output tubes are less important than many folks may think. Think about this. In the Hi-Fi world there have been many amplifier designs. Some such as the Scott and Fisher lines used EL-84 output tubes. McIntosh used 6L6 and 6550 / KT88 tubes. Dynaco and some British amps used EL-34 tubes. All of these amps, when operated at the rated specs generally stated that from 20-20,000 cycles at .5% distortion or less they were considered “flat” by industry spec. The output tube type had very little to do with anything. In guitar amps we purposely push the output tube beyond their design limits to make them distort. The difference between a Svetlana 6L6 and an RCA 6L6 is the difference in the way the tube sounds when it is pushed beyond it’s design limits. Being in the “tube business” this is not a great subject. What I am basically saying here is: Before you go to a pricy output set of tubes and a possible need to rebias the amp think about a simple phase inverter change. There are no amp adjustments necessary when you change the phase inverter.

In real life we rarely get to the point of pushing our output tubes to their limits. Our front end is going into distortion. Our phase inverter is breaking down too. The ratio of this front end distortion to phase inverter drive and breakdown is determined by amplifier design topology. You cannot make a Marshall into a Fender no matter how many people tell you that this can be done. Putting 6L6 tubes in a Marshall will NOT make it sound like a Fender either.
There are many 12AX7 types of tubes available. They are all different even though they are supposed to have the same specs. Even when one looks at the same tube type from the same maker out of the same production run we find HUGE variances. +/- 50% off spec is common. Most 12AX7s today show a current output of 0.6-0.8 milliamps where 1.2 milliamps is expected. You throw a 12AX7 in your PI slot with a 0.8mA output and you are 30% down on what the amp can do right off the bat. Your amp is not as full, tight, responsive, or just plain “powerful” or dynamic. Many of today’s high production amps use the Sovtek 12AX7WA short plate as a generic 12AX7. I have issues with these in the tone and gain stage but staying with the topic of phase inverters, these are just awful (12AX7WA Sovtek) for the most part. In tests these show very low standing current. The Ei long smooth plate also shows low standing current, even though a long plate. Generally, large plate tubes will show higher standing current but this is not always the case. The JJ ECC83S has the highest standing current of any current production tube. The JJ is a short plate tube. The JJ is an exception. You might think the JJ would be a good PI. Not from my personal taste. The way the JJ breaks down is not as musical to my ear in most amps and I do not care for the touch response and dynamics of the tube in the PI position in most amps. What do I like? I like the Sovtek 12AX7LPS and the GT 12AX7M. The GT 12AX7M is also available as a matched phase inverter from the SAG over at GT as the SAG-AX7- MPI. There is also an SAG-AT7-MPI. I have talked about matched phase inverters in other places prior to this piece of writing. The 12AX7M and 12AX7R2 (Sovtek 12AX7LPS) are both long plate designs. In either case I check these for specs because in all cases there is a wide range of variables from tube to tube and run to run in production.
There are a lot of great NOS tubes. They have advantages in the tone and gain stage but they are not as available as production tubes made today. When you are on the road or on tour these are harder to find. In the case of the phase inverter we do not want to stock a bunch of Mullards or Telefunkens to burn up every output tube set change. There are great current production tubes that give us all we can ask for.
Other great phase inverters to consider are the 5751, 12AY7, and 12AU7.
The bottom line here is simple. The phase inverter is one of the most important tubes in your amp and the hardest worked tube in the preamp section of your amp. It is how this tube breaks down that provides your output stage distortion tone, character, and amp feel.
Myles S. Rose


...and some more info HERE (http://www.guitaramplifierblueprinting.com/12ax7.html)
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on September 26, 2014, 04:14:55 AM
Hey SC great (edifying) read thanks  :thumb-up: So this is about the power amp stage of a normal guitar amp (which is a combination of preamp and power amp).  So my Carvin TS100 power amp has 4 12AX7s, one per channel input buffer and one per channel phase inverter, so P1 in this case is the 2nd tube (on each channel) which is the phase inverter (feeds the output tubes in my case 6L6s' 4 of = 2 per side push/pull) and if I changed the phase inverter tubes out to a 12AT7s I'd have a TC over 5000 and heaps more output current (which should equate to headroom, less gain but much more current).  IIRC there was a recommendation on Dougs tubes (I think ?) where they said a 12AT7 in the P1 slots works well.  I must try it sometime.
Title: Re: Place to discuss input/preamp tubes
Post by: darthphineas on October 16, 2014, 03:38:43 PM
when it comes to the total best QUALITY preamp tube for the original MP-1, and when you take cost out of the equation, which tubes are the best for the ORIGINAL, out-of-the-box ADA MP-1 tone?...that are currently available?  lol!

--- note, this is about a QUALITY product and the ORIGINAL tone ---


brand?
JJ? Tung-Sol? Groove Tubes (or Groove Tubes Gold)? Ruby? Mullard? Sovtek?


model?
12AX7?  12AX7A?  ECC82S?


other specs?
short plate?  long plate?
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on October 17, 2014, 01:15:45 AM
As you said the other thread seems more active, this is really the place for this discussion LOL, I've posted reply there as there are also posts from others already.
Cheers R
Title: Re: Place to discuss input/preamp tubes
Post by: darthphineas on October 17, 2014, 04:42:19 AM
Thanks for the reply. You seemed to be the only one that could cut to the chase and answer the question (what is the BEST that is closest to the original?).  lol!

Seems that when I bought those JJ tubes just a few years ago that I figured they'd last about as long as the last time I swapped tubes, which was quite a while back....and I'm probably playing less as well. haha!  If the JJ are the best, that's fine, so at least now I know. But there is another brand that has the same voicing that might have a longer life, that's cool too.

Seems like you like the Mullard tubes. What would you consider to be the basic difference between the Mullard and the JJ?  The Groove Tubes gold series ECC83S seems to get a lot of good reviews, even for clean settings.
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on October 18, 2014, 03:29:50 AM
It's a very interesting (and as I'm sure your gathering very subjective) conversation.  SCs advice has always been solid BTW (he got me interested in the Mullards way back), so if he's tried and likes the TADs (I haven't)... There probably isn't a production tube around these days to match the ones ADA used (particularly for pumping/vacuum) but there are some exciting options and I love the Mullard long Plates  >:D (no secret there lol)
While the JJs are good in MP1, they are different to the original tubes (ADA would have had them made to their specs etc as do other preamp/amp makers).  The original tubes were IIRC (been a while BTW) a bit more open than JJs (I'm talking Boogie STRs here BTW), although the original tubes were very old (years of gigs/rehearsals) and the Boogies were new so gave new life.
The basic difference I've found with JJs and Mullards is the Mullards are sooo articulate and 3D (and, as posted in the other thread, articulate tubes are less forgiving, they track everything good or bad... I like this aspect BTW but I've been playing for over 40 years).  I find the JJs tight, great gain and tone (best feedback I've ever heard) but a bit 2 Dimensional, they don't think outside the square (if that makes sense), the Mullards are so open 3D and go wherever your fingers want them to. I'm yet to try the Mullard short plates but will get to soon.
The other (and initially main) reason I didn't like the JJs in my MP2 was they broke up (in not a nice way) on the bottom E 82hz.  I put in the Mullard long plates and melted (what a sound, and I'm not easily impressed), but that's for me and my sound/style (I do miss the JJs feedback though).
GT sells good tubes, they don't make them but they know what they're doing (gold usually means gold coated pins so better electrical contact, less resistance, longevity of connection etc).  The Tung-Sol re-issues are also probably a good fit in this mix and made in the same factory as Mullards.
Title: Re: Place to discuss input/preamp tubes
Post by: trader144 on November 03, 2014, 04:01:28 AM
FWIW, I have tested the tubes SC recommended: TAD 12AX7A-C RT001

I agree with SC, they sound very, very close to the original MP-1 tubes. Hope they last as long.
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on November 04, 2014, 03:13:25 AM
Good to know, hope they last well also  :thumb-up:
Title: Re: Place to discuss input/preamp tubes
Post by: rabidgerry on September 08, 2015, 03:22:30 AM
Anyone ever used  Shuguang 12AX7B tubes?
http://www.ebay.co.uk/itm/Shuguang-12AX7B-replace-ECC83-Audio-HIFI-Vacuum-Tube-Valve-for-amplifier-1PCS-/251646444560?hash=item3a974c0410 (http://www.ebay.co.uk/itm/Shuguang-12AX7B-replace-ECC83-Audio-HIFI-Vacuum-Tube-Valve-for-amplifier-1PCS-/251646444560?hash=item3a974c0410)


And what are peoples experiences of Sovteks? 

http://www.ebay.co.uk/itm/261210575172?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.co.uk/itm/261210575172?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

I'm thinking of trying some in my stock MP1  (I've new TADS ordered for me 3TM).
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on September 09, 2015, 06:07:40 AM
I was talking with a tube nut mate of mine re Sovteks, he likes some LM model ones ? but his interest is in hi end audio, super clean. SC IIRC said they are good for phase spliter before power amp tubes (this is where you want current, not so much gain, e.g. 12AT/U/Y7s))

The Shuguangs seem ok from other reports, go with some Mullards  >:D IMHO
Title: Re: Place to discuss input/preamp tubes
Post by: MarshallJMP on September 09, 2015, 08:24:42 AM
Never liked sovteks in a mp-1.They sound dull.
Title: Re: Place to discuss input/preamp tubes
Post by: rabidgerry on September 09, 2015, 12:03:28 PM
I was just asking since I saw them aty a nice price.  I'll bother.

Besides my TADS arrived today so I shall try em out this evening I hope :)
Title: Re: Place to discuss input/preamp tubes
Post by: Soloist on September 09, 2015, 09:50:49 PM
When I got my stock MP1 it had some Groove Tubes in it(not original for sure). Sounded like an amp with a blanket over it.
Put a Mesa Boogie STR12AX7-A  in V1 and a 12AX7-SPAX7 in V2 and wow!!! did it wake the beast :metal:
While I feel the Mesa's are great sounding tubes they are a little sterile sounding compared to the rich warmness of the factory tubes.
I would like to try the Mullards based on rnolans recommendation. Add that to my to-do list.
Title: Re: Place to discuss input/preamp tubes
Post by: rabidgerry on September 10, 2015, 01:29:04 AM
Bugera talk these up quite a lot on there website.

I can vouch for the Bugera 12ax7 b  it sounds pretty dam good for my needs in V1

http://www.bugera-amps.com/EN/products/12AX7A.aspx (http://www.bugera-amps.com/EN/products/12AX7A.aspx)

I do not know what the difference in the models are so I have asked Bugera to clarify

http://www.bugera-amps.com/EN/products/12AX7B.aspx (http://www.bugera-amps.com/EN/products/12AX7B.aspx)

Deep and bold is how I would desribe the 12ax7 b and loud!
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on September 10, 2015, 04:40:03 AM
Well basically Bugera are doing what many others do (e.g. Boogie, GT, Ruby etc), they are picking the best from various suppliers, obviously they all go for low noise/microphonics, gain etc. But if you put a Boogie SPAX7 (their premium offering and usually a JJ ? from what I've read) up against a New Sensor Mullard reissue, they sound "quite" different. Both though are low noise/microphinics high gain. So from the many well tested options we talk about here, they are all low noise/microphonics, high gain etc. So it comes down to how they sound in "your" preamp with how "you" play. My 2nd MP2 came with EV 12AX7s, I wasn't impressed (but they were low noise etc etc). And blanket comes to mind as I recall them.
How/what you play makes a big difference to what will work best for you. The first tube change I did with my MP1 way back was to Boogie 12AX7s (coz I could buy them locally and hadn't thought about it much). They were fine and suited what I was playing at the time (much more higher gain than I do now). They are a very tight tube and IMO suit very high gain situations (as MJMP likes them (well he uses Ruby JJs, much the same short plate tube) in his 3TM). They also have the nicest feedback I've heard so far (important at those gains).  I tried some in my MP2, as posted elsewhere here, they were ok.. The Mullard long plates introduced a new dimension I'd not experienced before, they are so articulate and "3D" which really suited my current playing style, so right now they are my preference. Many here are finding a combination of different brands (in V1,2,3) works for them, you just have to try a few options/combinations to work out what you like. But at this end of town (i.e. they are all low noise etc etc) we are commenting on/ comparing the sonic differences. But based on my experience and other comments here for those that have tried them, the Mullard Long plates are definitely worth a try, even just one in V1.
Title: Re: Place to discuss input/preamp tubes
Post by: rabidgerry on September 10, 2015, 05:56:25 AM
I think I will try a long plate  but where the hell do I get them?  I've a lot of Mullards in my general searching for 12ax7's  but none of the long lates.

They are really expensive as well.

I need to find some more choices I like for I have two Peavey Rockmaster preamps and they have 4 tubes each.  One of them sounds nice with an EHX in V1.  I think I've Groove Tubes in the V2 3 and 4 positions.  This sounds ok.  The other Rockmaster has some other brand which aren't as to my liking as the EHX combo I have in the first one.
Title: Re: Place to discuss input/preamp tubes
Post by: rnolan on September 10, 2015, 06:34:16 AM
I get mine from Evatco here (http://www.evatco.com.au/product-list/?filter_product_brand=47, the 12AX7 is the long plate and the CV4004 is the short plate, they are both 12AX7s), but dougs tubes have both (http://www.dougstubes.com/preamp-tubes/12ax7-ecc83-7025/mullard-12ax7.html). You may get a good deal from Evatco though as the AUD is very low right now ? I got my last 6 tubes from Evatco as they are in Oz and all good  :thumb-up: Dougs has them for $20 USD, Evatco are currently $32 AUD less 10% GST (tax) to you (coz your not here, though I'd like it if you were LoL).
From another thread I'm getting that a Mullard long plate in V1 and 2 nice tight tubes in V2/3 is a good combination for 3TM. Hey I'd put in 3 long plates  >:D and crank the fu%k out of it, but I grew up living on the edge with very high gain Marshalls etc cranked up full and learned to tame it (not everyone's cup of tea).