Retubing a Delta Blues...

[duhvoodooman]

Just for grins, I decided to retube my Delta Blues. Wanted to have a full set of backup tubes on hand anyway, so this was a good opportunity to experiment a bit.

I bopped over to Eurotubes.com (http://www.eurotubes.com/index.htm) and found that they offer a variety of JJ Tesla retube kits for popular amp types, including the Peavey Classic/Delta Blues line of amps. Depending on the sound you're looking for, they offer several different tube combos, consisting of a quad of matched EL84 power tubes and various iterations on the three preamp tubes. The Classic 30/50/Delta Blues amps come with three Electro Harmonix 12AX7's as the stock preamp tubes. Depending on what you're looking for as far as headroom vs. distortion/gain characteristics, Eurotubes offers combinations of JJ ECC83S (12AX7 type, nominal gain=100), ECC832 (12DW7 type, a hybrid tube that's like half a 12AX7 and half a 12AU7, which has a gain of only 20) and ECC81 (12AT7 type, gain=60) tubes. Being lower gain models, these latter two give less volume & distortion and more clean headroom. The character of the distortion seems to change somewhat, too, being less harsh.

I chose the "Blues" option, which consisted of two ECC83S's in the first and last preamp tube positions (V1 & V3) and the ECC832 in the middle (V2) position, which is the gain tube for the lead channel. Eurotubes describes the Blues option tube package as follows:


"A matched quad of the JJ EL84's in a hotter grade along with a standard ECC83S in V1, an ECC832 in V2 to drop the gain and give a very natural blues tone and a graded ECC83S with a high current output in V3. These give a smoother tone that is great for Blues."

The tubes came today, so I popped them in the DB tonight and tested them out. The ECC832 certainly had the advertised effect. Volume and degree of distortion were reduced markedly. But even with the gain cranked way up, I could notice a smoother, rounder tone than the stock 12AX7 had given.

I also had a spare JJ Tesla ECC83S tube I'd bought a few months back for my VOX AD30VT, so I popped out the ECC832 and put the hotter ECC83S in, to compare the two head to head. Volume and distortion increased substantially (as did noise!), and the distortion took on a sharper edge. So while the ECC832 would be great for blues, this tube is probably better for a more aggressive rock tone. Certainly, it's better for shear volume, if that's a consideration!

I recorded some short audio clips with both tube setups, using both my Les Paul and my Strat. For the LP clip with the hotter ECC83S, I turned down the post-gain setting to get volume similar to the ECC832 clip. I recorded the same short riff three times in each clip, once at each of the three pickup selector settings.

For the two Strat clips I used a little different approach. To equalize the volume between the two, this time I backed off the gain ("Pre") setting. This not only reduced the volume but also tamed the distortion some. Still, I think you can hear the difference in the character as well as the degree of the distortion between the two clips. Crank up the volume a bit when you listen to them, so that you can hear the character of the distortion more clearly. Keep in mind that I'm dealing with fairly low levels of distortion ("overdrive" would probably be a better description) throughout this exercise.

Here are links to the four clips:


Strat with ECC832 in V2 (http://duhvoodooman.com/audio_clips/Strat_ECC832.mp3)

Strat with ECC83S in V2 (http://duhvoodooman.com/audio_clips/Strat_ECC83_S.mp3)

LP with ECC832 in V2 (http://duhvoodooman.com/audio_clips/LP_ECC832.mp3)

LP with ECC83S in V2 (http://duhvoodooman.com/audio_clips/LP_ECC83_S.mp3)

Let me know what you hear when you listen to them!

For now, I'm leaving the ECC832 in, so I can play around with it some more. If I need more distortion, I can always stomp on the ol' Bad Monkey....

[Spudman]

I just re-tubed my Classic 30 and I absolutely love it. I gigged with it last weekend and it performed way above my expectations. I don't even know what tubes I put in it. The others had lost their zip over the years so I'm sure anything new makes a huge difference. No rattles, no micro-phonics just tons of grins. I'm retiring the Hot Rod Deluxe for a while cause the C 30 works so good.
When I decide to quit being lazy I'll post what I put in it.
I'll probably do the JJ's for the Hot Rod when I get some $.

[r_a_smith3530]

For you guys using JJ tubes, don't just order off the web. Go the extra distance and give Bob Pletka (at Eurotubes) a call. He's a great guy, and quite knowledgeable about both the JJ tubes and about Peavey's Classic Series amps. If you go into detail regarding what kind of sound you're after, he will hand pick a set of tubes for you.

[Spudman]

That's what I have in mind for my next set. He is talked about very highly for his knowlege and customer service on some other forums. Nobody ever complains. Plus you get a product that you are very happy with. Try that Walmart!

[duhvoodooman]

For you guys using JJ tubes, don't just order off the web. Go the extra distance and give Bob Pletka (at Eurotubes) a call. He's a great guy, and quite knowledgeable about both the JJ tubes and about Peavey's Classic Series amps. If you go into detail regarding what kind of sound you're after, he will hand pick a set of tubes for you.
I was very impressed with the experience of dealing with them as it was, and the tube set I received appears to do just what the description said. But if I do this again, I'll definitely give Bob a call. It's great to hear that you can get that degree of "personal attention" at Eurotubes!

[SuperSwede]

Voodoo, I would really like your recommendation on a replacement tube for my Tonelab. The stock tube is a Electro Harmonix 12AX7. Im looking for a little more headroom.

[Nelskie]

I was very impressed with the experience of dealing with them as it was, and the tube set I received appears to do just what the description said. But if I do this again, I'll definitely give Bob a call. It's great to hear that you can get that degree of "personal attention" at Eurotubes!
I have a J & J re-tube kit in my Peavey Classic 30, and J & J's in my Valve Jr. Nothing but great things to say about Bob, his products, and the fantastic service. About a year and a half ago, I was waffling about getting a different tube amp, and was referred to Eurotubes by a friend. Am I ever glad I did, as the re-tube kit I put in my Peavey amp turned it into a absolute tone monster. Previously, I'd re-tubed it with Groove Tubes, and it sounded pretty good. Not fabulous. Pretty good. The J & J tubes pushed that amp into a whole different dimension tone-wise - so much fatter, definitive, and more complex. Truly, an amp that you can drop jaws with totally by itself - as in "look ma', no pedals!"

Bob's definitely "in the know" with making Peavey's Classic and Delta series amps sound their best, and if you are considering one of these rigs for yourself, or already have one, I'd make Eurotubes your first stop. Call him up, and tell him how you want it to sound. He'll send you the right tubes. When I talked to him, I said, "vintage Aerosmith, with a little Zeppelin, and some 70's Stones & KISS for flavour". It's exactly what I got! :D

[duhvoodooman]

Voodoo, I would really like your recommendation on a replacement tube for my Tonelab. The stock tube is a Electro Harmonix 12AX7. Im looking for a little more headroom.

Then you're looking at trying a lower gain tube in your Tonelab. I did a quick Google search, and it appears that the most common substitution is the 12AT7, which has about 60% of the 12AX7's gain. You can go even lower than that, but from what I've read, the lower you go, the more likely that you'll degrade tone, as well. The other one to consider would be that 12DW7/ECC832 tube I mentioned above, since it has an overall gain of about 60, also. If one of these two still doesn't give you enough headroom, you might even go as low as a 12AY7 (gain of ~45). I would expect that the 12AU7 (gain of ~20) would be too low, and tone would be out the window.

Here is a list of the approximate nominal gain ratings for the more common preamp tubes. Most have a couple of different names, depending upon whether the British or American designations are used:


12AX7/ECC83: 100
5751 (Mil spec 12AX7): 70
12AT7/ECC81: 60
12DW7/ECC832: 60
12AY7/6072: 45
12AU7/ECC82: 20

Keep in mind that these are NOMINAL ratings, and current tube production can give very high variability from tube to tube. For this reason, it's a good idea to buy from a reputable dealer who stands behind their tubes. Some go as far as to pretest tubes and only sell those that are well within spec. You may pay a couple bucks more, but it's probably worth it. Since you're only buying a single tube, that's not a big impact. You should be able to get a good quality current production 12AT7 or 12DW7 for somewhere in the $8 - $15 range. If you want a NOS (new old stock) tube in one of the revered older brands (GE, RCA, Amperex, Siemens, Mullard, etc.), it will run you a LOT more. Unnecessary, IMO, for what you want to do.

Let us know how you make out....

[SuperSwede]

Voodoo, so I guess that there could be audible differences between 12ax7 tubes from different manifacturers as well? I have read on a few sites that the use of other tubes in the tonelab than 12AX7/ECC83 is possible, but I am not certain that I dare to try myself.

[duhvoodooman]

Voodoo, so I guess that there could be audible differences between 12ax7 tubes from different manifacturers as well?
Yes, absolutely, but that would tend to be hit or miss. Trying a lower gain compatible type would be a surer bet, IMO.


I have read on a few sites that the use of other tubes in the tonelab than 12AX7/ECC83 is possible, but I am not certain that I dare to try myself.
I wouldn't worry about it at all. The 12A_7 tubes are all compatible, from everything I've read--you're basically just walking up & down the gain ladder. And enough people have obviously tried the 12AT7 substitution in the Tonelab to qualify it as zero risk, in my mind. Go for it, Swede!

[SuperSwede]

Well I am going to need another tube eventually anyway so I might as well try 12AT7, and at 10-15 dollars its not that big deal if I dont like it.