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down for information on Byrd's amplifcation set up and tips to get the
trademark Byrd tone and improve yours
The
amp is stock except for a 'fail safe' mod to the mains transformer and
rereouted wiring to reduce noise. The Marshall 8x10" cabinet is one of the key ingredients to the Byrd sound. The highly regarded cabinet is a monster in every way - tone, volume, bass response, weight and height. Produced from the mid 1960's to the early 1970's, the 8x10" is one of Marshalls hidden gems. The speaker are original 10 watt Celestions with Alnico magnets. They have been re-coned to original specs. James' current signal
path is as follows: Other
Amplifiers Son Of Man Byrd's Amplifier Tone Tips These tips are specifically dedicated to non master volume tube/valve amps (particularly old Marshall's) but the principles apply for all amps. 1. How old is it? If it's any more than 4 years old, get the filter caps replaced by a qualified amp tech. Do NOT EVER attempt to do this yourself. They store enough voltage to kill you EVEN when the amp is NOT plugged in. The 'fatal' level voltage charge can persist as long as 8 months! That's what these things (Filter caps) do; Store up reserve 'juice' to ease the loading on the transformers. After about 4 years, they "run dry" and the amp's performance and even safety can become a real problem. They are very similar to batteries in that they are filled with 'gunk' that stores voltage. Replacement should always be undertaken on a used amp unless it's nearly new (Time wise). 2. Have a look at the tubes (Output). I would not assume they were bad by any means. In fact, they could well be better than anything you'll be replacing them with, so make a note of the brand name and model numbers and try to identify them carefully. You might want to remove them for special use (Recording) if they're something amazing like Gold Lion brand. [webmaster: This answer is aimed more towards mint original vintage amps]. 3. Assuming the output tubes are of high quality and in good shape, my advice would be as follows: Leave them alone, but while you're having the other work done (filter cap replacement), have the bias adjusted by the tech to factory specs. Do not allow anyone to talk you into changing the bias setting for a "Hotter" sound. While some players do this, you're not doing the amp any favours and frankly, I think "correct" bias sounds the best by a long shot. 4. Qualify the tech's ability to actually do the work properly. A proper bias adjustment requires an oscilloscope AND a variac. If the tech tries to tell you he's some kind of genius who's going to do it "By Ear", find another tech! These tools are essential to do the job properly, and I'd run away from any guy who tried to sell me his services without them. 5. You don't actually have to have an amplifier specialist perform the work. Any GOOD radio and television repair shop can perform all the work listed as long as they have a schematic and the bias specs. [AC: Valuable information can be found in books such as 'The History of Marshall' - Michael Doyle , and 'The Tube Amp Book' by Aspen Pittman]. 6. You can probably save yourself some money by just emailing Marshall and asking for the specs + schematic if you need it. I am not certain whether the differences between the export versions and the domestic versions specs are actually listed differently between the Big Marshall History books on their respective sides of the pond. 7. Using the amp. Expect to go through a LOT of output tubes when running one of these amps full up, particularly with a speaker attenuator [Powerbrake or THD Hotplate]. My own only last 30 to 40 hours of playing time. I almost never use my Marshall for everyday playing, only recording because of the expense involved. Remember that each time you must replace your output tubes, you should also rebias the amp to original specs. 8. It may be worth your while to purchase a training video to learn how to safely do your own amp maintenance. I don't know what things are like elsewhere in terms of finding guys who'll do the work at a reasonable rate. But to at least give you an idea on my end, it's quite cheap if you know where to go. The parts themselves run about as follows: Tesla EL34 tubes about $32.00 a pair. Filter caps run about $15.00 each. The time to do both operations shouldn't bill more than an hour. "Matched" pairs of tubes are overrated in my opinion. A few hours of high volume playing pretty well evens out any advantage that might initially be there with a closely matched pair. 99 out of 100 times people who claim to have "Matched" pairs of tubes are full of shit anyway as it requires special testing equipment to tell whether they're matched anyway, and this equipment is neither currently still made, nor likely to be found outside a manufacturing facility for military use tubes. Groove Tubes DO in fact have the equipment to do this and sell matched sets, but if you want my advice, seriously, save your hard earned money. Their tubes are fine, just very over priced and not worth the difference. Also, stay away from tubes made in China. They are of very poor quality. All that can be said for them as of this writing, is that they work, but sound? Nope. Remember, setting the bias itself on a class A/B amp matches the tubes for the most part anyway. If you get the "hard sell" on matched sets, consider that neither Yngwie nor I are bothering with them and I think we both get some pretty good tones. 9. Speakers, settings and microphones: If you don't like what you're hearing after getting everything going, realise that these last 3 elements are crucial to finalising the sound you're after. If you can find them and or afford them, alnico speakers are your best bet. Of course you know I love the vintage 8X10 cabs, but short of that (And you know they're pretty near impossible to find unless it's become a holy grail mission as it was for me), use a 4X12, nothing smaller, or it will (naturally) sound smaller. You need a certain amount of cubic feet of air space inside the cabinet itself to acheive the right sort of bottom end on your tone. The "right" kind of bottom end does NOT come from cranking up the bass control. It comes from a well matched amp/cabinet, and volume level. I do NOT recommend Celestion "Greenback" 25 watt speakers btw. I think they're truly horrid sounding speakers, and the entire idea that this model was "The classic Marshall sound" of the late 60's/early 70's is absolute rubbish. Neither Hendrix, Clapton, Blackmore, Trower, nor anyone else associated with such a claim used these things. They used the G12H30 designed for the 4X12 "Bass" cabinets to achieve "The classic Marshall Sounds" of those periods. the "Greenback reissue" breaks up horribly on low notes (Sounds like a beer fart!) and are very harsh sounding on the top end as well. Stay away! If I were you, I would go ahead and buy a 4X12 Marshall in tattered condition (Save your money for the important things here) and make certain it either contains the Vintage 30 "Reissue" (Yet more B.S. from Marshall as it's not a reissue of anything they ever made) as it's a very good sounding speaker in it's own right. It's not an alnico, but they did a very good job on it none the less and I've recorded with them myself with good results. In fact those are the speakers I was using on the first Atlantis Rising album. A word about microphones: When you hear a guitar tone on an album that you like, realise that what was actually coming out of the amp, and what ended up "In" the production are in all likelihood VASTLY different. In other words, sitting in front of a blazing Marshall "Properly" adjusted for good sound, and hearing the same track picked up by a microphone, then sent to tape, then in all likelihood having some EQ'ing done, are not going to be the same experience of sound. This is where becoming an experienced player/recording artist really comes into play, and it's frankly beyond the scope of this advice here to really go into all the variables here. But DO understand that what sounds good standing in front of the amp, may well sound like utter crap 50 feet away, or vice versa. Mic placement, room size and acoustics, these things are so variable that I can't really offer anything as gospel other than to advise you to do a LOT of experimenting and (Very important) basic recording of the sound to learn how it can work. 10. Last but FAR from least, use the biggest, thickest speaker cables you can find to hook up the amp / cab / powerbrake. Also keep them as short as possible. You wouldn't believe the number of guitar players I've seen using GUITAR CHORDS!!! to make these connections. Dumb dumb dumb! I recommend nothing smaller than 10 gauge speaker cable (That's a full size larger than the speaker wire Marshall provides with their amps) to hook everything up on the power side of things. If you can find #8, even better. The smaller the number, the thicker the wire is. The amp will run cooler, the damping factor will improve (The way your speakers react to the power amp impulses), and your tubes and everything else will last much much longer. And the use of a regular guitar cable to hook up the amp and cabinet is an almost certain major repair bill and likely to cause a fire as well. Sorry to seem as though
I'm overstressing this so much here, but unfortunately, I've seen it done
so many times by otherwise intelligent musicians, I had to make certain
you knew. I've got photos of Jimi Hendrix in concert with fucking guitar
chords between his heads and cabinets! Most of the old "Marshall
amps blow up a lot" stories come from this very common and stupid
practice. Now I don't want you to get the idea here that you've just bought
yourself more than you bargained for in terms of an impractical guitar
amp or doubts about to that effect. Vintage type Marshall's are entirely
sensible amps, and actually VERY reliable when handled properly. I've
used them off and on since the early 1970's with nary a problem, and any
of the handful of problems I did have were entirely avoidable had I had
the knowledge then, that I have today. (I made the classic 'guitar chord/power
amp mistake' as a lad myself). But consider the thing a Ferrari of sorts.
If you want the best, and intend to drive fast and hard, take a little
time to learn how the thing works best before you go full tilt and you'll
have no problems. |
