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jetboy

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About jetboy

  • Birthday 01/19/2022
  1. a hopefully final question? Im seeing various listings for power dissipation on el-34 tubes, some list them at 20 watts max and others at 25 watts. Is this variations in manufacturer or should they all be closer to 25 or 20 watts max. Also what about the 6ca7 which are listed as 25 watt tubes, since they are supposed to be a direct replacement for the el-34 are they also more like 20 watt tubes or 25. The ones I have are not groove tubes but EH?
  2. Hi Myles you were right. I just got some more specific info. The previous info was from a generic sheet that had referred to. The specific info was that the plate voltage was 470mv and that I should be biasing from 25-29 for the el-34 which makes much more sense according to everything else I've been looking at. Also turns out they were saying that they did not recommend the kt88-6550 tubes as they drew too much voltage. So I can use 5881s or kT66s etc. Anyway thanks for the help. Looks like getting the info to and from them directly is waaay more accurate.... Im guessing some stuff got lost in translation. Plate voltage is measured at pint 3. Pin 5 will be your bias voltage, around -50 or so volts. Today's 5881s are really 6L6 tubes so I do not see the harm in using them. The NOS Tungsols would also work quite nicely as would the other NOS 5881s at a proper bias setting. I personally feel their bias recommendations are too high. You will get a wider playing range if the tubes are biased a bit cooler just out of crossover notch distortion.[/QB]
  3. Thanks myles, I got some info back from the guys at Heritage amps (they were with Holland before) and they gave me some values to use at the test points for el34s which Im trying right now. They had 30-37 mv for the 6l6 and 35-40 Mv for the el34s. Im using 38+ for a bit more grind. If I get ambitious Ill pull the chassis and measure at pin 5, will this give me the plate voltage? The test points supposedly give the current draw, according to Heritage. Have you got anything to go by that just uses the current draw, Id rather not have to pull the chassis if possible for some reason in their info back they said not to use 5851s. Would that indicate that the plate voltage is too high for that type tube? I have that question into heritage now. I know there is a formula for this, can I use the info I got from heritage as to current draw, and the wattage dissapation of the tube to infer plate voltage or is this something that just needs to be measured? Thanks again. Have a good turkey day!
  4. hi myles, long time no chat but then Ive been pretty problem and question free! anyway still read ya on the various boards and here too. Got a rather simple question, I picked up a used Holland lil jimi amp. Very nice, super clean the way it has been set up. Not a problem but... I noticed on the amp label that it says el34/6l6 model and it has a bias pot and test probe inputs on the back. To my way of thinking this means that I might be able to run el34s and the like in the amp as long as I rebias it via the probes and pot? The amp is seriously overbuilt tranny wise... what do you think? My understanding is that Mike Holland was secretive in that no manual or layout was provided with his amps, there is not even a tube chart so I'm left guessing as to where v1 and v2 etc is. there is also a secret unmarked ¼ jack on the chassis. Also the Holland amp co is out of business as heritage has taken over those designs (kind of). Although I love the clean tone out of it as is, Im very curious as to what it would sound like with say el-34s or maybe kt66s in it.
  5. thanks Myles, turns out I couldn't get the sound of the slant v6 outta my head so I returned the univalve and made a deal for the Carr had to give up the badcat and some other gear but all in all I'm now hearing the sound in my head. When I added up the cost of the univalve + tubes and a 1-12 or 2-12 cab the total was going to be a higher cash outlay than the trade + some cash for the Carr addition by subtraction as they say, thanks for your time and advice. Now I gotta learn to play better
  6. I know that was a convoluted ?, so thanks for getting to it. so what your saying is the nature of a univalve is to be on the bright side? and since i'm running it with 10" speakers that probably makes it worse? is an el34 tube part of the problem? can i use a 6l6 or 6v6 to counteract the basic briteness that i'm getting from the current setup? I will also try the 12ax7c and 12ay7 in v2 and v1 as well. thanks again, jetboy
  7. hey Myles, long time no questions (from me anyway ) quite a while back you helped me set up my badcat cub with some suggestions on nos tubes. Worked out great and I'm still using the preamp tubes. This year I got the itch to get some more fendery type sounds and had been thinking univalve so I could adjust it to taste. I was ready to buy it when I came across a Carr slant v6, I really liked the tone and overall sound and was ready to trade the badcat for it but couldn't swing the deal dollar wise. so back to plan "a" I got the univalve, played it at the store on a 2-12 cornford cab, it sounded a bit trebly but useable. When I got it home all I had to run it with was a 1-10 weber c10nq open back or the badcats 2-10 celestions. With the stock tubes I thought I was going to pierce and eardrum, it was that shrill. The only way I could get it under control was to pretty much turn the treble knob to "0" and the bass to "10", this is pretty much with any of my guitars but especially with my strat with kinman avn blues. this guitar does NOT have this problem with the badcat or any other amp I've run it into. Is this normal with the stock el34? or is it the 10's I'm using? I was really shocked, I've been tweaking it and swapped preamp tubes (a 12at7 in v1 and an ay7 in v2) and I got to a reasonable sound but.... I guess what I'm asking is is it the tube or the speakers? I'm leaning toward the tube because even using the line out and direct recording it I'm still using teble at 9 o'clock and bass at 3 o'clock. I don't currently have any power tubes to swap into it so I guess I'm looking for a recomendation. I've never owned an el34 amp before, would a 6l6 or kt66 be sweeter? or at least tame the treble? I do plan on a 2-12 cab or at least a 1-12 cab in the future but I'm getting to the dollar amount that get's me back to a swap of the bad cat for the Carr slant v6. and that's a sound I'm having trouble getting out of my head (I really liked the Carr) I just don't get it, after all the hype and subsequent backlash on the univalve I don't recall reading about anyone having this problem. most time people love'm thanks in advance mark f/jetboy
  8. check out www.kcanostubes.com or www.watfordvalves.com for different opinions of the CV4004. I'm currently using a CV4004 in V1 of my BadCat Cub and like it very much, V2 is a JAN NOS GE 12AX7WA. I like those better than either the OEM Sovteks or the various JJ ECC 83's although the JJ's are better than the OEMs
  9. Hi Myles, Just checking in with the prelims on my tube search: got the JJ's first and basically swapped them for the oem's except for the reverb and rectifier tubes. a 90/90 balanced ECC83 for the phase inverter and a low gain 78/79 ECC83 for v1, an unvalued ECC83 for v2 and a matched low gain (40) set of EL84's. the sound was good, a bit more clarity but not particularly remarkable. switched to the high gain ECC83 (114/118) in v1, very bright, pretty much too bright for me. very articulate. all other tubes remained the same. switched to the normal 97/98 ECC83 and that was better, good articulation, good highs but not too bright. overall the winner. went back and forth between the high gain and normal just to see if I was remembering it all. pretty much ended there with the normal tube being my fav. then I got the NOS tubes from Kcanostubes.com. left the ECC83 phase inverter but swapped the JJ EL84's for a matched set of NOS JAN GE EL84's, a NOS Mullard 4004 at V1 and a NOS JAN GE 12AX7WA at v2. WOW, this appears to be the combo. very good tone at all volumes (except totally wide open master and volume) very sweet sounding, very articulate without being harsh, good bottom and very nice mids. Now this was all very unscientific, since I changed many variables from the JJ's to the NOS, but right now the Cub sounds just great. I want to experiment more and try combining the JJ's and NOS here and there. Any suggestions? How important is v2 to the total sound. I know from reading your articles on preamp tubes and power tubes that they both make differences but since I got low gain JJ EL84's would that make a bigger difference then the NOS Preamp tubes? any thoughts would be helpful especially since I'm starting to doubt how much I remember about each setup. Also how careful should I be regarding touch the tubes with my fingers (skin oils, not being burned) I know that tungsten light tubes will get hot spots where you touch them, do tubes get weaker from that kind of handling? So far I've been wearing exam gloves to reduce finger prints. anyway I'm going to start swapping tubes again and see where that killer tone is coming from. Is there any problem putting the high gain ECC83 into v2 with the Mullard? how about the GE 12ax7WA into v1 and something else into v2. and is there any real advantage to another Mullard in v2? matched tubes? I guess I'll find out, eh? thanks for your support, Mark
  10. Hi Myles, after reading everything I could find, I went crazy (must be the old age) ordered the NOS tubes including a mullard 4004 and a NOS GE 12ax7 and el84's and THEN ordered some JJ's from Bob at Eurotubes. The JJ's are a balanced ecc83 for the phase inverter and a variety of graded ecc83's with a set of lower value el84's to reduce some volume on the Bad Cat. Man I'll have enough tubes to last a lifetime, at least my lifetime. Too much info!!!! I guess the analysis part of all this got to me, I'm just gonna try'em all and see what I like. I figure ultimately it will be cheaper now then later and I'll pretty much know the limits of the Bad Cat and will be able to decide for myself whether all this NOS stuff is for real or just for people (like me I guess) with too much time on their hands. Harkens back to my youth where I spent way too much time thinking about hifi gear ;-) or my (current) other hobby/job Mac computers. talk about anal..... I'm starting to think like the posters at HC, looking for the holy grail. good thing I still have some $ left over from selling my Super. My kids will just have to allow their ol' dad a few eccentricities and a little less inheritance. the Torres was fun, I probably should rewire some of it to reduce the hum a bit but it was as you said a real learning experience, especially learning the hard way about capacitor discharge, wahooooo. I felt the same way about the SG, it was what I wanted BAD in high school, I settled back then for an Epi w/ 2 mini buckers but that neck was even worse as far as neck play... I finally got my '67 to celebrate my 2nd daughter's birth but the reality was not as good as the dream. Turns out that one of the PU's had a short and was a single coil (previous owner removed the covers) I never realized it, so maybe I just didn't get the best it had to offer. The guy I traded it to for the Bad Cat sent the pu's to lindy fralin to get rewound. Looks like he's fixing it up to get some real $$$ for it. Maybe you'll see it on Ebay or someplace like that. Same thing with the '78 Les Paul I got when my 1st daughter was born, I can now say I had one but it was also less than I expected and I traded it for some computer gear. As you can probably tell I've been at this off and on for a long time and it pretty much coincides with times of major change in my life... some people opt for comfort food I seem to opt for the comfort of music. I suppose/know if I had the talent I would opt for a career somewhere in the biz. Anyway thanks again for your advice and for the friendly conversation. The business may be nasty but you still meet some mighty nice people in it. Mark
  11. Myles, thanks for the incredible reply, from reading the posts here and at HC I'd say i'm getting advice I should be payin' for so thanks for your dedication to making amps sound better. As for the last part of your post, funny i already did that the year before. I knew I wanted the real deal (TUBES!!!!) and I'd been searching for that full out sound of my former Super Reverb but with a lot less volume. I ended up building a Torres Tiny Tone ($400 + $120 for a small cab and a weber 10) which was fun and it did give me pretty good tone at speaking volume but the versatility wasn't there, no clean tones to speak of and no reverb. Ended up playing it as an effect into my Super (with all the clicks and pops and still too much volume). Bought a pod ($300)and that was better, more versatility and a fake reverb and stopped using with the Super. Still not quite right but closer. Then I had my latest bout of what could only be called male menopause ( I will be 50 this month) I finally decided it was worth the effort and $$. I bought a custom built JET guitar (hence the Jetboy moniker) and traded my '67 SG, which I never really liked as much as I thought I would, for the Bad Cat and sold my '68 Super. Now here's what ever wisdom I can impart to those in NEED of that tone. You can do it the long way or just break out your wallet ;-) So much for the rambling.... I pulled the tubes from the Cub and they are all sovteks, and the rectifier is a Ruby. I'm going to order some JJ's and give'm a try. Also after going to your web site and reading the tube tests I decided to go for broke (literally) and order a combination of a NOS mullard 4004 and a NOS ge jan 12ax7 and a set of NOS ge el84's from KCnostubes. I guess I'll find out whether there is real or just poseur (me) tones in this rig, after this it certainly won't be the amps fault.wAN8qE I know there will be some that will moan about dumping the Super, and it was a real nice amp but way too loud for me (the Cub is still too loud but not as bad) and the Super needed some real overhauling, caps and tubes etc. again thanks so much for the help on this and i hope someone is paying you for all the time you spend here and at HC. Like you said, 20 years from now my daughters boy friends will be playing the Cub wondering who will inherit it. Mark
  12. Myles, you are amazing, I'm just getting back into all this after some time off for kids, I'm finding all kinds of info both here and at harmony-central. Can't imagine how you keep up. Anyway, like I said, just getting back at this. Traded some old gear that I didn't need/want and bought a new rig. A Badcat Cub Reverb, a 15watt class A. 2 EL84's, 2 12AX7's in the preamp, a 5AR4 rectifier and a 12AX7 phase inverter. I like the amp and to me it sounds pretty darn good as is, however in reading some reviews about it, other users are replacing the OEMs with NOS tubes and they claim major improvement. Well I'm all for that but not so sure where to put the $. Badcat supposedly uses a Chinese 5AR4 and ruby tubes for the power section, not sure about the preamp section. After reading/lurking most of the amp section at HC seems like some NOS tubes would give an improvement but where should I start? The rectifier seems like a logical choice since there seems to be agreement that the Chinese tube is less than stellar and maybe a NOS tube in V1. Any thoughts on this? Seems like I could spend another $200+ and retube the Cub with all NOS but that seems like overkill at least for what I do/want. Am I just experiencing major GAS from reading all this stuff about amps again? thanks so much for all the time you spend on the boards giving out so much info to the uniformed. Mark
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