Gitfiddler Posted October 21, 2014 Posted October 21, 2014 I really enjoy small, (old or new) tube amps. Nothing sounds quite like a raging little over-achieving tube amp. All of the harmonics, distortion, natural compression and just plain sweet tones that come from one of these little beasties is great for at-home fun. However, I've noticed that no two amps sound the same or even have the same volume level. More specifically, I've compared two reissue Gibson Les Paul GA5 amps with each other; two Fender Rivera-era Champ II's and two Super Champs of the same vintage. While each of them sounded great, no two have the same volume. Swapping output tubes (Original GE's, n.o.s. Electro Harmonix or new JJ's) back and forth made little or no difference in volume. Preamp tubes made more of a difference in tone and break-up, but did not affect volume. Swapping speakers did make a difference in volume, but not so much in some of them. The GA5's have identical Weber speakers that sound different from one another. And the Champs original speakers all sounded different. Dropping in a Ragin Cajun (thanks, Yoslate) woke up one of my Super Champs, but it was already the louder of the two. Even after replacing the other SC's original speaker with an Emi Legend (75 watts!), the volume was still less than its brother's. With louder, more powerful amps, the sonic differences are more difficult to tell (at least to these old ears), but small amps tend to be more telling of what's really going on inside of their chassis...good or bad. What do you guys recommend to increase volume of a tube amp?
Gitfiddler Posted October 21, 2014 Author Posted October 21, 2014 Thanks, but extension speakers or connecting to monster amps is too obvious. I'm trying to get the most out of these little boxes that spend much of their lives in bedrooms or jam rooms.
Billgelder Posted October 22, 2014 Posted October 22, 2014 What do you guys recommend to increase volume of a tube amp?
schundog Posted October 22, 2014 Posted October 22, 2014 I was pretty impressed with how well my new overdrive pedal, the Electroharmonix Soul Food worked as a clean boost, with the gain turned down quite a bit, level up.
RhoadsScholar Posted October 22, 2014 Posted October 22, 2014 If you want to make it louder, I was taught to put a more efficient speaker in it. the 10 inch Rajun Cajun speaker is a good example as it has a db rating of 106 vs approx. 95. To me it is just a spec of 7db difference, but the amp you put it in would get louder. I have developed a liking to for the way the rajun Cajun speakers sounds. Those would be good candidates for the SuperChamp and they are only about 79 new. In summary, the db rating for the speaker makes the most difference regarding the loudness of the amp. You may or may not like that particular speakers tone. But it would be louder. Too bad you are in San Francisco (alumni of USF) or I could let you borrow one.
yuominae Posted October 22, 2014 Posted October 22, 2014 If you want to make it louder, I was taught to put a more efficient speaker in it. the 10 inch Rajun Cajun speaker is a good example as it has a db rating of 106 vs approx. 95. To me it is just a spec of 7db difference, but the amp you put it in would get louder. I have developed a liking to for the way the rajun Cajun speakers sounds. Those would be good candidates for the SuperChamp and they are only about 79 new. In summary, the db rating for the speaker makes the most difference regarding the loudness of the amp. You may or may not like that particular speakers tone. But it would be louder. Too bad you are in San Francisco (alumni of USF) or I could let you borrow one. That makes sense. Since loudness is a logarithmically related to DB rating, a 7db difference would make a big difference in the loudness you get out of it. But doesn't it depend as well on the power output by the amp to the speaker?
bolero Posted October 22, 2014 Posted October 22, 2014 agree with Bill & the mic! also a more efficient speaker try plugging one into a 4x12, they will sound huge and the volume will be louder as well otherwise...they are what they are....low volume amps. at least you can crank the snot out of them without blowing the roof off!! ps my Vibro Pig is probably the result of the same line of thought: a princeton reverb with 6L6's instead of 6V6's
Gitfiddler Posted October 22, 2014 Author Posted October 22, 2014 I already installed a Ragin Cajun in one of the Super Champs and it sounds GREAT. For variety, I installed an Eminence Legend in the second Super Champ. Volume did increase in both amps, but the second amp still has considerably less volume than the other. Also, I've connected them to extension speakers, making them loud enough to gig a medium sized room with! Amazing little amps. My question for you 'amp whisperers' ...Is there another internal component that can increase amp volume? Also, is less volume an indication that the amp needs a cap job, tube re biasing or something else?
slider313 Posted October 22, 2014 Posted October 22, 2014 My question for you 'amp whisperers' ...Is there another internal component that can increase amp volume? Also, is less volume an indication that the amp needs a cap job, tube re biasing or something else? Yes, a new set of transformers or sometimes just a slightly larger output transformer. Less volume could be a number of things. Most components in older amps were + or - either 10% or 20%. After years of use there's also component drift. That's one reason one amp of the same model sounds different or better than another. Another thing that would cause less volume from two amps of the same model; plate voltage. That plus or minus 10% to 20% also applies to transformers. Some time ago I had picked up a '64 Deluxe Reverb in excellent condition. My intention was to tune it up and sell my '65, which is in very good condition. My '65 had more volume, punch and sparkle. I crossed each over the others speaker with no change. Then I took some voltage readings; the '64 had 410v on the plates @ 20ma and the '65 had 435v on the plates @ the same 20ma. More voltage equals more punch and clean headroom. That's the main difference between the Vibrolux and Pro Reverb amps; other than the speaker size. The Vibrolux run those 6L6's at 410v where the Pro run them in the 440v range. They have the same output transformer but a different power transformer.
rjsanders Posted October 22, 2014 Posted October 22, 2014 what works for me in comparing two amps, regardless of vintage or model - adjust bias - use PaulC tim or timmy - use external cab with EVM-12L (i've made an extension cord for older amps)
Gitfiddler Posted October 22, 2014 Author Posted October 22, 2014 Jeff~ Thank you for your usual expert comments!! I knew there had to be something going on within the innards of these old amps. I never realized that there could be a possible 10% to 20% variance on internal component (transformers, etc.) efficiencies. Plus, as you stated, the age of these things is a performance factor...kinda like us!
High Flying Bird Posted October 23, 2014 Posted October 23, 2014 Take two athletes who are twins. One will always be better than the other. It's just the way it is. Nothing is exactly like another of it's kind.
yuominae Posted October 23, 2014 Posted October 23, 2014 That would be the reason why we pay so much money for the "holy grail" guitar, even though it's specs should really make it identical to any other guitar of the same model, right?
Billgelder Posted October 23, 2014 Posted October 23, 2014 Take two athletes who are twins. One will always be better than the other. It's just the way it is. Nothing is exactly like another of it's kind. Ron, you are certainly one of a kind!
peterbright Posted October 24, 2014 Posted October 24, 2014 Rebiasing is a cheap way to go but you will decrease the life of the output tubes. I'd leave them the way they are.
Gitfiddler Posted October 24, 2014 Author Posted October 24, 2014 Rebiasing is a cheap way to go but you will decrease the life of the output tubes. I'd leave them the way they are. Isn't the purpose of adjusting the bias of each output tube to maximize performance by matching them? Or are you concerned with setting the bias too hot? If so, then I agree, that would decrease tube life.
rjsanders Posted October 24, 2014 Posted October 24, 2014 boutiquers are likely by design to set bias for a target sound, but others (notably Fender) were known to just grab a pair of power tubes and plug 'em in. which may be the reason i was not knocked out by most Blackface amps i heard in the '60's. they were biased cold. Rivera-era ones were biased to produce max. output (my Concerts all put out 60w, if they still had the original tubes (Syvlania STR357's? i forget). anyway... btw, Graham @ Wolfe's told me about his trip to Heritage Amps some time back. he said once an amp was done and ready for test, everybody'd gather around and play it and critique it. adjustments included biasing. darn, i'm sorry PaulC isn't designing amps.
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