jazzcaster

Hello Myles, I hope all is well at Groove Tubes et al! I'm hoping that you or some of the other knowledgable people here can elaborate on the difference between a 1x12 and a 2x10 speaker configuration in a combo amp? (sound wise, I mean). I'm looking at a Traynor YCV40, and it's offered in both configurations (all other aspects of the amps are equal). I notice that Peavey has a similar offering with their Delta Blues Series amps as well. I don't understand comments like "tighter bass end". What exactly does that mean? Volume between the two is not really an issue for me (both will be plenty loud for my needs). I'm looking for some versatility in the amp to play jazz, blues, country and classic rock. No metal. Any input would be much appreciated!

Hello Myles, I have no question, I just wanted to mention how much I appreciate your forum and the professional advice and help that you offer people. You helped me a while back with my new Fender Pro Reverb, and it's been singin' ever since. I often check in here for my "amp educating" and am never disappointed. You have no idea how refreshing it is to read (and get!) some intelligent, accurate technical advice without an overbearing or sarcastic tone. And it requires a lot of talent to communicate those things to the many non-technical people, over the internet, to boot! Your mom should be proud of you!

Hello Myles, A quick amateur question here, if you don't mind. I have an 8" speaker (from a Randall practice amp)that has absolutely no markings of any kind on it (nada, zilch, zero!). No spec sheets or anything at the website to help, either. If I want to determine the impedance, and do not have the means (or know-how) to conduct an impedance bench test (ie: under load), can I simply measure the DC resistance? I believe the DC ohm reading will always be less than the "nominal" rating of the speaker, but it will be close. Is this correct??? Thanks in advance!

Thank-you Myles. My speaker question had nothing to do with my Pro Reverb though....I'm totally happy with it now (as a result of the tube changes!). The speaker question was for an old Princeton Chorus I have (a righteous little amp btw!). keep playin' Paul.

Hello Myles, I am really enjoying the new Pro Tube Reverb, and am still astounded by the sound with the tube change. Your advice was excellent and very much appreciated. Thank-you again. I have a general speaker question though. I have read some postings on other sites respecting speaker upgrades (specifically to Weber speakers...a C10CA, and a C12N). A number of the postings state that the speakers need to be "played/broken" in, and that the sound keeps improving as this happens. Years ago I was assured by a credible source that my Hi-Fi stereo speakers did not have to be "broken in". The sound I heard now was the sound I was always going to hear. I assume Amp speakers would be the same? (no play-in/break-in). Is this an old wives tale or truth? kind regards, Paul.

Hi Myles, Bias, bias, bias.....yet another question... How much "lee-way, free board, etc." is there when setting the bias (before you damage something, that is). And how much of a change in bias is really significant? Fender gives a bias spec of 30ma for the new Pro Reverb. I am reading through Dan Torres's "Inside Tube Amps" book and his chart gives a bias setting of 25.7ma (voltage of 465, class A/B, 6L6 tube). The lower the ma, the colder the bias, correct? Is 5ma or so either way going to make any difference I can hear? (or damage the tubes/amp?). Dan suggests setting the bias "by ear", that is, set the bias, play through it for a few minutes, then reset/adjust til it sounds right. This makes sense to me, but I don't know the min/max I can go with the adjustment before something is damaged. I have Svetlana 6L6's in now, an upgrade from the stock Sovteks (I noticed an improvement right away). Thanks Myles, best regards.

Hi Myles, Just a short update on my Pro Reverb vibrato problem (Lots of noise, not audible at 1/4 power setting). It was, in fact, a defective tube (V6). I replaced the stock Sovtek with a Jan GE 12AX7WA and its fine....quiet, and works great at 1/4 power setting. I didn't really suspect a bad tube because the amp was brand new. Live and learn.....thank-you for your help. How are you making out with your customers Pro Reverb that you've been working on? Best regards!

Thank-you for the suggestions on the Vibrato issue Myles. I'll try this and give you some feedback on it afterwards. Cheers!

Hi Myles, I am indebted for life for your help with the Pro Reverb tube section ID. I muddled through the schematic and managed to identify the reverb and vibrato, but was lost on the rest. I'm off to the races now. My only concern with this amp is that the vibrato channel has a lot of hiss, very audible. And the vibrato is not really audible at the 1/4 power setting. Is there a tube change I can make to quiet it down (and increase the "audibility on the 1/4 power setting?), or is this the nature of the beast? Does the Pro Reverb you are working on exhibit this problem? The hiss does not change with guitars (ie. it's not noisy single coils that are the culprit) and there is no problem on any of the other channels. My Peavey Delta Bluse 115 tremolo(vibrato) is much, much quieter, and thats what I'm using as my benchmark. Thanks so much again Myles for your help. (I'm learning more on your forum page in the past few days than from any other source, ever).

Myles, Thanks so much for your great info on the new Pro Reverb. I will keep in touch and hope to hear more after you've had a chance to delve further into the amp you have. As a note (hey...I can actually offer "you" some info!), I swapped out the stock Sovtek 6L6 Groove tubes (I had no real problem with them, I'm just a tinkerer at heart) and replaced them with som Svetlana's. WOW! Did I say Wow?! I've heard many good things about this 6L6, and now I know why. My clean channel sounds....well....cleaner, if thats possible. I guess "more sparkle" is how to describe it in cliche terms. But the real treat is the overdrive. It is buttery smooth compared to the stock Groove Tubes. (I play a Strat with Van Zandt Blues pups). I adjusted the bias to the Fender spec of 30mv. I had also adjusted the bias on the stock tubes when I first got the amp (they were slightly "cold", if thats the term (26mv). Once I figure out the pre-amp tubes, I'll start a bit of swapping to feed my curiosity. My God this amp has me jazzed!!!

A quick question for Myles! I have a new Fender Pro Reverb (Pro Tube Series). I love it. I want to experiment with some tube swaps. My question is....which tubes (ie. function, like tremolo, reverb etc.)correspond to which location on the chassis (ie. V1, V2, V3 etc.). I have the schematic that came with the amp, but I don't know how to read it....it's almost all Greek to me!). Thanks Myles (or anyone else who can help).