Originally Posted by YMI5150?
Alright, I'm jumping in. New to the tube scene and this has been overwhelming...but very cool to read. I'm an engineer/tinkerer so I'm liable to get totally sucked in along with you guys.
I've got a TSL601 with unknown upgrades. I am an early VH tone chaser and get the whole tone in the hands thing.
I do believe that I can make some changes to my setup to get that clean yet crunchy sound that Ed, Warren, G Lynch, Angus all had back in the day. I'm beginning to search for a half stack to help out but am hoping that you can summarize all this testing into a few preamp tube winners. I started a thread on 601 upgrades and Marty had great input but I could use a little more direction (which brand 12Ax7 black plate?, what test results to look for, etc.). You mentioned some having more sensitivity to vibration and not being a good choice for a combo.
I'm also hearing that I should leave the power side of things alone until after these mods are done and re-evaluate. Concur?
I am like you Josh, I don't turn it up much past 2-3 very often. Hopefully there's a decent solution at lower volumes...
Any chance of putting together an executive summary for an ongoing tone chasing project? Like a progress report so-to-speak...
I'll post feedback once I get a few to try out.
Cheer and this is awesome. Keep it up!
Wow! Great to see ya over here in the mecca of Tube Mechanics 101.
I think it would be sort of difficult to condense these seven pages into a couple of paragraphs. I will however try to answer your questions.
First off, I think I already gave you some advice on the differences between open and closed back cabinets. The 601 is the same as my 602, but it only has one 12 and that ain't gonna do it. I actually think you should get a good 2 by 12 cab, before doing any tube tweaking, but that's just my opinion. You will get immediate bass response with an extra 12, so think about that.
Black Plate tubes were only made by a few manufacturers. Other manufacturers bought these tubes and put their labels on them. The most sought after BP is the RCA. These tubes exhibit a punchier mid sound to them. Guitars are basically tenor instruments, so you are looking at low-mid's up to mid-highs. If you want a punchier mid, the BP is the way to go. The other manufacturer that I like for BP's is Raytheon. They made really good tubes in their day.
And yes, preamp tubes have long, medium and short plates. The shorter the plate, the more rigid the plate structure. This translates into less vibration and microphonics. Some manufacturer's made tubes that were "ruggedized" and were capable of taking more vibration, regardless of plate length. Combo amps are very hard on preamp tubes and when picking NOS or current production, it is best to buy the one's with medium or short plates. I have recently gone against this in my quest for tone by using tubes that have longer plates, but astronomical gain. If I ruin them, I'll blame Josh and Joe.
Yes, I would try and get a better cabinet, then play with the preamp tubes and then, if necessary, change the power tubes. Power tubes do sound different, but it can be a subtle change most of the time. If you have good, trained ears, you should be able to hear the nuances of the different brands of power tubes. Here again I will note that Black Plate power tubes are highly desirable, but are damn near impossible to find in an EL34. RCA made some BP 6CA7's in the 50's and they go for about $200 a piece when available and that is out of my price range even for two.
If you do not play very loud, it would be advantageous to have higher gain preamp tubes so your window of sound shaping is larger at lower volumes. When I switched over to the super high gain 12AX7's, it was astonishing to discover that I had a lot more tweaking capabilities with my amp. My tone controls sort of jumped out at me. My sound between the pre and the master was different. I think one hot tube is all you really need and I have the best luck putting it in V2 (just my opinion). "If" the high gainer lasts in my combo, then I will consider putting the BP back in there with it. That produces a one-of-a-kind sound. Otherwise I may just put bot of them into my TSL100.
If you can spend the time to read all of the pages, you'll see that there is a lot of info being hammered out. I know that it is a lot of reading, but I go back and reread certain parts all of the time. You got in at a good time, because Joe, Josh and myself will all be posting new info. I have been using my TSL122 as a test bed, because Josh has the same amp and it sort of gives us some experimental credibility. However, I do have several 602's and I might try some tubes in it. However, both amps have speaker mod's and they are already fitted with NOS USA tubes, so they're really not stock 602's.
Once again, welcome to the thread.