Newbie- Just bought a hd 410 130 and appeciate input
Fell in love this w end and bought an amp I know nothing about! Glad to see you guys here and hope you can tell me lots of things and I apologize, I have many questions and not sure where to post-
1. Is there a way to figure out year, or other info from the sn?
2. Speaker switch is set to 8 ohm, but when I count the speakers it looks 4- can anyone help me determine if this is the right setting?
3. One of the casters is dead- ideas on fixing/replacing without damaging any 'rarebird' quality? Also the chrome is rusty and all the metal is grungy- Cleaning suggestions?
4. Started to do some research and found that some like this amp as a bass amp, and I play bass, so could be a real 2 for 1-but I have lots of questions-
a. I see an external speaker jack and assuming I can plug a 15 inch here- But what ohms and wattage would be the right match?
b. since this is a combo, would the 15inch defeat the 10s, or would I end up with 10s and 15 at the same time?
5. Tubes- The dealer told me it has 6v6s in place of ELs that were originals? Can anyone help me understand the voicing and advantages of different tube configurations?
What sold me on the amp was the big clean, brighter and fuller than a twin sound on the reverb ch. Keeping the settings static, my frankenstrat can take it from clean tele bridge to slightly overdriven blues with the cool rail in the neck.
By rolling all the bass off, I can get an almost workable crunch off the first channel (at the same settings), but it's still got a lot of the 'fenders don't overdrive all that well' going on.
Guessing I will put a pedal in front for overdrive/crunch (and always open to ideas), but also wanted ideas on tubes- not sure I should mess with anything at all-
And also don't understand the triod inverter tube- What does it do?
And frankly, I always thought that tubes in the preamp was the trick- Why does this amp sound so nice with a SS preamp?
Lots of questions and hope I haven't overloaded you guys-
Any and all input appreciated!
Member for
10 years 7 months
Member for
9 years 2 monthsgreat input
Wow mm210! I had expected lots of responses with puzzle pieces, but looks like u gave me 95% of what I needed- big thanks.
Will look it over 2nite and provide more details .
And wonder if the bassist s were using the head version like a fend bassman? In that case,unplug 10s and plug in 8 ohm 130 cab to try out bass?
Big Thx!
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10 years 7 months
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10 years 7 monthsSomething's not adding up
..if you ask me. JJ's 6V6S tube is limited at 500V, so unless the amplifier has been modified substantially the tubes should not be 6V6. The older MM amps were designed for 6CA7 which is very similar to the European EL-34. EL-34 is limited to 800V (not sure what the old Sylvania 6CA7 was limited at, but probably something similar) and so is able to work with the ~ 720V plate voltage in the MM amps. Anyway - I suppose the amp could have been rewired to use 6L6 at some point but I'd rather not speculate and merely suggest you look at what may be printed on the existing tubes.
Personally I wouldn't chase distortion in a 130W MM amp - at the very most you can achieve a nice compression from the 12AX7 on the the low power setting. The advise in the old brochures about how the master volume should be operated at '10' unless special circumstances (like, oh I don't know, fear of going deaf) dictate otherwise is a bit out of date by now when we're dealing with the 130/150 (Heavy Duty as MM called them) amps.
For crunch, use a pedal - they have come a long way since MM amps were new. I agree with Mike - excellent amp for bass too - with a closed back cabinet of course.
Cheers,
Lars Verholt
Member for
9 years 2 monthsAre there Els that look something like this photo?
Thanks Lars and Mike- I've designed some of the funkiest guitar circuits you will ever hear (ask me about my all on series strat with a coil roll off if you're interested in quack) But I have to fess up, that it's all by ear and I know just enough about AC to stay away from it- so maybe I'm missing things you would immediately understand.
I didn't pull the tubes, but I looked at them and the best I can tell, the 2 center tubes (rt side of the cabinet) look much like the red letter and 6v6 on this photo- Are there any ELs that look a lot like this? Or should I go ahead and pull one (I don't ever touch tubes if I can help it;)
There are 2 shorter, gray bottomed tubes on the left and right of the tubes in the photo- Should I pull and photo them?
And I did confirm there is a little tube on the left of the cabinet- I hear it's a triode tube, but have no idea if that is part of the tube equation we are evaluating. Should I pull it as well?
Dealer clearly said that 6v6 were interchangeable and considering I just bought it Saturday, I would think I have room to return this if we think it's jury rigged and likely to implode- So open to documenting alternatives asap and really appreciate you guys jumping in so rapidly!
Best regards,
Michael
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10 years 7 months
Tubes
The EL series are USUALLY a little taller and skinnier. Here's one. The E34L version is just the supposed heavier version. Kind of concerned about having mixed tubes in there from different manufacturers. That's USUALLY not a good sign. Even JJ 6V6's won't take the strain cap'n! Mike.
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9 years 2 monthsMember for
9 years 2 months6L6s of different sorts- Ok, now I'm really, really confused-
They aren't 6v6s after all- They are all 6L6s- I dont know what that is-
1. The two in the middle are taller - There is an example with photo 1
2. The ones that are far left and far right are very old GEs and are considerably shorter than the 2 middle one- Although they both read 6L6, the 'basket' on the one on the right is different than the one on the left (by basket, I mean the gridish thing inside the the end where the pins are)- The one on the right is rather rectangular like a small bandaid- The one on the left is more circular.The 2nd photo is one of these GEs
So can you help me understand what these tubes are and what I should do? Considering it works and I love the sound, I hate to mess with it- On the other hand if it's not going to last I would like to contact the music shop-
Open to any and all ideas and clearly out of my league
Member for
10 years 7 monthsIt's 6L6
It makes sense now. So, you have one of two situations going on:
1. The amp was correctly converted to 6L6 maybe 30+ years ago when everybody (including Music Man) thought EL-34/6CA7 would disappear
2. The amp is stock but somebody put 6L6 in it - which is asking for trouble in the long run
At the very least you should find out if you have situation 1 or 2. If it's 1 and you like it, play it and enjoy it. If it's 2, I would suggest investing in a matched quad of EL34 and get the amp adjusted properly.
Cheers,
Lars Verholt
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9 years 2 months1979 RD65 112
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9 years 1 month
2 or 4 tubes in HD130 212
I recently had a tube failure on my HD130 212, it blew fuse and when I replaced it it sparked and smoked a little bit so I unplugged it. This happened during last set of a 3 hour gig. I ordered 4 new JJ EL34L's and am wondering if should have tech install all of them. The amp was only running 2 at the time. I have the SS version preamp. I only play it on 3 for preamp volume. and 3 on master volume and run it at full power. Will it run too hot with all 4 tubes? Thank you. I am new to this forum.
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9 years 2 monthsMember for
9 years 2 monthsUggh can you guys provide ideas for my hd130 tubes?
Well, I had a year of of awesomeness with my HD 130. If you look above I had a 6l6 tubes but it finally died last week and the technician says the amp was never set up for 6l6s.
He wants to change to 6ca7 which I know nothing about and I imagine it will greatly change the sound of the amp. I really love the sound I had for a year very warm bright with incredible dynamics. Anybody have any ideas on what might get me the sound I had before?
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10 years 7 months
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10 years 7 months6CA7 vs 6L6 wiring.
Per schematics, the wiring difference between 6CA7 and 6L6 is minimal. A 6CA7 should have 1.5 kOhm resistors to bias the accelerator grid (pin 4) in each tube (R63 and 64). A 6L6 tube would use a 470 Ohm resistor to bias the accelerator grid (pin 4). Take a look inside and see what value resistor (R63 and 64) is connected to pin 4 on the tubes and that will tell you which tube to use. 1.5 kOhm for 6CA7 tubes. 470 Ohm for 6L6 tubes.
http://pacair.com/mmamps3/sites/default/files/docs/2100-130.pdf
http://pacair.com/mmamps3/sites/default/files/docs/2475-150_and_2275-15…
Good Luck. -mgriffin
Member for
9 years 2 monthsUpdate on 130 6ca7 tubes
Guys, thanks for all the input- it's been crazy on multiple fronts, including the new tubes- Tech installed EH 6ca7s (sorry didn't get to try the JJs) and sound seemed good for a few 10 minute tests and overall I was happy- the voicing change seemed minimal-
However, it's first extended performance (recording session 45 min plus) was way bad- it started humming after 30mins or so and when I finally got bad enough that I went to take a look, 2 of the tubes were glowing, smoking etc)... back to the tech who re biased and says all is well with the same tubes-
But once I got it home, I noticed it was set to 4ohm speakers (I'm pretty sure we established that 4*10 is 8 ohm, can you guys confirm?).
So now, I'm wondering if I should be looking for a new tech or should I try another burn in period?
Mgriffin, I do a lot of exotic guitar wiring, but totally avoid the interior of amps because I'm afraid on all fronts;)- so I have no idea what the resister values are- I assume I would have to drop the amp out of the chassis? I hear MMs are hard to open up and thinking it's not a good idea for me to go this route, but please give me some confidence if I am wrong;)
So trying to be patient, other amps are getting a workout and I'm not plunging back in until I get some feedback- this is too great an amp to screw up-
Way, open to ideas and thanks again for a great, great place to communicate-
Peace,
Michael/Mickey/Zstrat
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9 years 2 monthsMember for
10 years 7 months
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9 years 2 monthsMember for
10 years 7 monthsHard to tell
Dunno what to tell you - if your new set of tubes had one or two bad ones in there, it could cause the amp to fail (hopefully without irreparable harm). If your tube set is OK, but the amp has a weakness somewhere, you need to find out where it is before you either put yet another set of tubes in, or you put the amp back in service with the same tubes. Using a variable transformer would allow you (or your tech) to find out if there is a badly failed component somewhere by running the amp at, say, 50% line input power for a while. Of course sometimes this test yields no results - the failing part only misbehaves at close to full operating voltage. Also, bias adjustments should be done at or very close to actual running conditions because the tube amp circuit is not entirely linear except for at a relatively narrow operating range.
Sorry to sound like a politician here - it´s hard to get really into the details without the amp in front of you.
To follow up on Mike "210"¨s question: The older 12AX7 phase splitter circuit had an inherent risk of catastrophic failure due to the design of especially the feedback loop. A high frequency oscillation (frequencies well beyond the human ear's capabilities) in the output section could cause output tube destruction or OT meltdown - or both. Mind you, I am not saying you had a situation like that going on, but a problematic 12AX7 tube could indeed cause unpredictable issues in this type of MM amp, just like the driver transistors and related bias components are often the culprit when the later type MM amps display instability.
Put the amp on the bench, hook up a load resistor in place of a speaker, feed a test signal to one of the inputs and hook up an oscilloscope - preferably with two channels so you can monitor both goezinna and goezoutta at the same time.
Hope this helps,
Cheers,
Lars Verholt
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10 years 7 months
Yeah Lars, THAT'S exactly
Yeah Lars, THAT'S exactly where I was heading. I've had one pf those. I even converted it to SS driver but didn't like the sounds afterwards. Went back. THAT'S the amp I dropped the pliars in while it was running and smoked it! Anyway, I have always wondered if there was a better way to tame it. I have a 2-10-65 that runs just fine and have never (knock on wood) smoked the tubes. The 130 head I had DID. I have always wondered if just biasing them a LOT cooler would help with the problem but never fixed my 130 so I never had a chance to try it. OR maybe putting a variable feedback control in it to reduce the feedback. I don't know, like I have said, I'm more of a mechanic than an engineer. I have always been under the impression that the PI tube WAS the cause though and a GOOD quality tube was essential to the tube burning problem. Don't know. Some seem to do it and others are fine. I never fixed my 130 because geez, who need 130 watts these days!
Mike.
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10 years 7 months
HHMMMM? Just re-read the
HHMMMM? Just re-read the post a little bit. from what I remember, when the PI tube models went chernobyl, ALL the power tubes lit up. If you had just two do it, which two did it? Maybe it was loosing bias voltage? Just guessing here. Also, I never had good luck with EH tubes in MM's. They just won't take the voltage to me. Mike.
Member for
9 years 2 monthsHD130 is home!
The guru in the Raleigh stays really, really busy (Yontz, http://www.madscienceworks.com) but he worked on the MM last week and found the following-
1. One of the pin guides is broken and tube not properly seated
2. One of the speakers was disconnected
3. Tubes weren't matched at all
So the bottom line is it appears that the previous amp guy's mis-biasing heated the tubes and all is now good- And it shows that it's worth waiting for the guru;)
Thanks for all the good input and will move away from the EH when time to change tubes-
Much peace,
Mickey
Ok-let's start at the top.
Ok-let's start at the top. First off, that's NOT a bass amp. You will ruin the speakers playing bass through it. First look and see if it has a 12ax7 tube in the little metal shield. If it does, it's say 75-78. If it has no tube it's later. Are the badges silver on black or black on silver. Casters, any pop in caster will work. Chrome, hard work, steel wool and if all else fails, just replace them. If it REALLY has 6v6's in it, they won't last. They are NOT designed for the voltages in that amp. It should be set on 8 ohms. THat's the only amp that should, with 4 speakers. Any speaker plugged into it will ADD to the impedance as the jacks are in series. Oh, I see later you DO have the 12ax7 so it's 75-78 or so. Tone is ALWAYS subjective and the early MM's always sounded better to me but for guitar. I am NOT really a tube guy for bass. Anything I missed? Mike.