MT15 update post - great success!

Goran Lorencin

New Member
Joined
Feb 27, 2021
Messages
233
Location
Ljubljana, SLOVENIA
Hey there folks, well after quite a few different posts and a bit more fiddling with ...
- the tubes (JJ E83CC in V1, Mullard 12ax7 in V2 and TAD 5751 in V6 - there was one bad Mullard and one bad JJ and were swapped), most of the noise went away
- effects (changed the order a bit, still think I might have a bad compressor pedal, the Supermoon reverb is awesome, but is in a way a bit noisy, still useable)
- 4 cable method with noise gate trough FX loop (which used to be "a noise issue", but isn't any more)
- the speaker (made a new custom back for the cab, replaced one of the V30's with a Jensen Jet Electric lightning)
- the cables (made my own Mogami and Cordial cables with Neutrik and G&H jacks)
- the knobs (that I have pimped to different shape and colours ... and you can really hear a difference in the airiness of the upper mids;), but looks cool

... it looks like it's smooth sailing almost by chance. Still have to find a small noise issue I think, but it could just be my ocd ... the sound is amazing. Hope I found the sweet spot for my gear, time will tell. But what a difference a bad tube makes, would not have thought.

To all of the brothers with the bothers, wish all of you the best with your gear! It is so cool when everything just works as it should.

Cheers!
 
But what a difference a bad tube makes, would not have thought.

Everything that passes signal affects the sound of the signal. Of course, in a tube amp, the tubes are super-important components. They amplify the signal, which means, they amplify any noise, including their own noise.

Bad tubes are noisy, hence, a bad tube will amplify the noise along with the signal. If you think of the tube as a crucial part of the signal path, it makes complete sense that a bad one will make a very substantial difference.

A great sounding tube will ALSO make a difference, but it's more subtle.

The tube in V1 does the most amplifying of the preamp signal. So it's the most important tube in the preamp chain. New tubes labeled Mullard are simply Russian New Sensor tubes branded with the Mullard name, and imported by Electro-Harmonix, a US company that owns the name now. This is now common in tubes - Genalex, Tung-Sol, and Mullard are no simply re-branded tubes made in Russia and China, and Telefunken are re-branded JJs, make in the Czech Republic (and JJs are pretty good tubes), though the Telefunken go through a somewhat different process than the standard JJs.

People want the traditional names, and often don't realize they're simply buying the same stuff they could have bought before from EH, New Sensor or the Chinese company that brands the Genalex tubes.

The older, NOS Mullards made in England by Mullard at their Blackburn plant, and sometimes by their sister company, Philips until around 1980, are very robust tubes. And they sound less strident and 'ringy' than most of the new production stuff.

I've never had an NOS Mullard, NOS GE, or NOS RCA go bad. But they're costly, and are hard to find sometimes. I'm always on the hunt for them, though!

I've had an NOS Telefunken go bad, same with an NOS Brimar. So you never know - I'm told by Doug Sewell that NOS Brimars they got for the initial run of DG30s were iffy.

JJs are usually very good tubes and last a long time. But every so often, you get a bad tube.

I could go on and on about new vs new-old-stock tubes. The closest to the manufacturing quality of the old tubes are the JJs, in my humble estimation. If you look at the construction and wiring, they aren't a rat's nest like some of the other stuff.

Blah blah blah, I realize very few here give a rat's ass about this stuff. But Rick does, so hi Rick! ;)
 
Last edited:
Thank for clearing that a bit more LSchefman. And exactly because of that I put the JJ E83CC in V1, I should maybe also try swapping all other original tubes that I still have inside, to see if that changes anything for the better. As many of you said before, it is most important to trust your "tube guy", as that can make life so much easier when you do not need to be in doubt if the tube you got is ok or not. For example the 12ax7 Mullard I bought (just one), came in a pair, they sent me a matched pair, two boxes taped together, and later I heard why, the second "extra" tube they sent me (and I was wondering what kind of business sends you double of what you payed for) was bad ... looks like they knew one was bad.

As a tube amp novice I must say I love how you can change the character of the amp with using different tubes, but it is very confusing buying tubes these days as there are 101 versions of one type, relabeling, and you never know if you got a good or a slightly worse one until you put it into your amp and play. I would wish for a store where I could come with my gear and just test different tubes, I would be willing to even pay for the testing, and also take into consideration paying extra for NOS if they sounded that much better (and would not have an "out of this world" price tag). But where I live there are not many shops with tubes and I have to order online, wait for it to come, install it and hope the sound is what it should be for the specific tube. It can get pricey very fast if you get on a tube testing - sound searching quest ... and reading forums, posts, articles about tubes does not help much as they sound different in different amps, so you really got to have a personal experience with them installed in your amp and playing trough your gear. Because that bad "dark" or "muddy" sound for someone is just the right sound for someone else, saying that just because many say JJ˙s are dark, muddy, lifeless and so on. There are many variables to take in account when talking about the sound - guitar pickups, pots and the electronics, the cables, the cab speakers, outboard gear, ... ... ... but you have to have experience to know the sound is bad because of a bad tube. And it was because of that that it took me quite some time to start figuring out why was my amp sounding as it was.

Here I could also get (besides other standard names) some Yugoslavian Ei Niš 12ax7 NOS tubes (supposedly made as copies of Telefunken or with the machines from that factory), but I`m not sure if they are a good choice for my MT15. Also the guy selling them does not offer a chance to test them before buying. Just curious, does anyone have experience with them in an MT15 or similar?
 
Last edited:
There are too many tube sensors to select. I got a Behringer 12AX7A for fork music signal processing. However, The Behringer tube sensor not works well on signal processing such as Rock musical signal processing.
 
There are too many tube sensors to select. I got a Behringer 12AX7A for fork music signal processing. However, The Behringer tube sensor not works well on signal processing such as Rock musical signal processing.
What the what ... the what?

Fork music? Did you mean folk music? Should I be actually asking that?

Link to a pump and pressure sensor manufacturer from China on "sensors to select"?!? ... ... ... I do not know what to make of that, but that usually does not happen by accident.

Did you use google translate on a dialect of the Uyghur language or what?

Honestly, what have you been smoking kane8907? ;)
 
Back
Top