MartyStrat54

Here is an except from my last round of tube swapping:

I then took a Mullard (that we'll call M1) that measured very stout and replaced the BP with it. There was a slight drop in the "big gain" sensation, but not much as this tube tested 104/106. Some of the bottom end that I liked went away, but still not bad. The clean was very chimey and touch harmonics would just ring like a door bell. Swapping the M1 and the ICBM made a difference on total gain characteristics. The clean channel was more creamier sounding (and some people prefer this). However, this arrangement made the number 2 and 3 channels awesome. I was able to crank the pre up harder. So now I am thinking maybe the ICBM should be in V2 with a Mullard in V1. However, I put the RCA 7025 back into V1 and "Wow!" what a sound. This is how I finally left it.

RCA 1961 7025-V1
RCA/Mullard 1964 12AX7-V2
GE 1959 12AX7-V3
GE 1959 12AX7-V4

Today I took all of these tubes out and brought in two RCA Black Plates. These are the 12AX7WA's. These tubes tested below 100, but above 92. Still would be considered NOS. Also in the mix are two GE Black Plates. One tests hot and the other tests lower, but still is good. So, we are going to go all BP on this test. I put the strongest RCA WA in V1 (94/96). Then I put GE1 in V2 (106/108). I then put GE2 (92/94) in the tone stack and WA2 (87/84) in the phase inverter position, V4.

Turn amp on. TSL122. I play a little and does it sound good. I can tell that I have a stout tube in V2, just because of the way the pre/post controls act. Again, the tone controls are very sensitive and that would be from the solid GE BP in the tone stack. These tubes give a very, shall I say darker, bluesy tone. The low mid's are very thick and this appears to be covering up some of the highs. My Man O' War speakers are sparkly and chimey, but these tubes have smoothed out the high end of the speakers. If I boost the highs, I get them, but I think it takes away some of the overall sound quality by bringing in some hiss. Not much, but I can hear it with my ears. (54 year old thrashed out ears.)

Conclusion: Too many BP's. The sound was good, but not what I'm after. My prior experiments have proved that one, maybe two BP's is the magic number.

Left V1 and V2 as is and put in the short plate GE's (that I originally had in the 122). Turn on amp. Much better. Now she is balanced again sound wise. I'm back to having that great blend of tone and controls. Gee, those little GE short plates sound good. Maybe that's why I had them in there in the first place.

Left V1 and V2 as is and put in the M1 and M2 Mullards. The M1 is a stout one so this puts a stout tube in V2 (GE1) and V3 (M1). Turn on amp. The hot tube in the tone stack doesn't really do much to the overall gain. It sounds good though. I take M1 and put it in V1 and I take WA1 and put it in the tone stack. Wow, what a difference. She's big and ballsy now. The WA sounds great in V3. Great overall "chime" to the sound. My speakers are perky and brighter sounding. Yeah, this is a good tube set up. I really like the sound.

V1-Mullard High Gain-M1-Medium Gray Plate
V2-GE High Gain-GE1-Medium Black Plate
V3-RCA 12AX7WA-WA1-Medium Black Plate
V4-RCA 12AX7WA-WA2-Medium Black Plate

I don't think the phase inverter cares whether it has a black or gray plate. With this in mind, I really only had two BP's in the active positions. Just like my other setting (see far above), I now have a gray plate in V1, but it is a hotter, high gain tube. Not so much as the ICBM or the Raytheon BP, but still pretty hot. The GE1 is an above average high gain tube as well. So it seems like I'm the happiest when I have two high gain tubes in V1 and V2.

Side Note: I measured 14, 12AX7's that were all made in Russia. Only two of them measured with above average gain. The rest were "new" tubes that just barely tested good on my B and K. This is a pretty good test result of what to expect when buying "new" tubes. They test good, but do you think you will hear a difference in your amp between "new" tubes and USA NOS tubes that are measuring 142? Sure, not all are that stout, but most of the tubes I am buying are in the 92 range. That beats the hell out of a 72.

Closing note: I am awaiting more tubes. Yes I broke down and I have bid and won more tubes. I'm still not done yet. However, in the bank are two more Black Plate GE's. One is super strong and the other is just good on one side and strong on the other (40/32 and 52/32).<Different tube tester than mine.
Also, I have the four Amperex tubes coming and my latest big buy was a lot of four RCA and four Sylvania's for $83 bucks, or just over 10 bucks a tube. I am aslo bidding on mor black plates. One of the lots of six tubes just went up while I was typing in this info. Maybe too high. There is a pair I'm looking at as well.

Once I get those Amperex tubes tested, I will be doing tests with them adding them into the mix. They are supposed to be some of the very best tubes made in Holland back in the day.

I also am going to have to come up with my own grading system for all of these tubes. I just ordered 100 white cardboard tube boxes for 12AX7/EL84 type tubes. I will be going back through my tubes and grading them for balance and power. I think if they are over 110, I'll call them "supers" and 90 to 109 will be "high gainers. 70 to 89 will be "regulars."

Marty