well, from my tube amp studies and trying to soak up what I could from the web and brief encounters like at the store, I see that nothing actually replaces being able to screw around with one a-z.
I picked up a couple of those fender gretas. 2 tube jobs ax7/at7. it seems that my LP is too hot for these amps. even if I just crack the volume. I even totally disconnected the bridge pup to see what only one does, but still hot.
are these amps biased more towards the right side by the redplate zone?
does this indicate the gain is really high, like maybe either the master section or input section is dimed by default?
is this the kind of issue that mods get made out of?
from having my little SS dean markley like 10watt combo, which actually sounds good for SS, with the input gain and drive switch then the master, I can dial in anything on that guy. to imitate what I am feeling on these gretas, I would turn the input gain up pretty high and then work it from the master volume.
is there still a sweet spot even though it has to be worked very subtly?
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so to off topic my own thread, I ran an RCA connector off the bridge pup and drilled a little hole in the electronics cover plate to let it out. sounds pretty crazy with one pup each having its own greta. a super clean would be awesome. then I could mic it and run like ping pong delay from the clean channel.
Then run the other one nasty with like flange or something else that adds to nasty. I have 2 mixers so this could even expand to 2 effect chains at once, me working the volumes and tones from the guitar..idk, stuff to horse around with, but I would love a crystal clean sound too.
"from my tube amp studies and trying to soak up what I could from the web and brief encounters like at the store" sounds like a really bad start.
What do you mean by 'the redplate zone'? Because it has nothing to do with breakup from too hot pickups.
..you needed to read the rest of the sentence, as that is also my conclusion.
so anyway, im asking questions to get more of the picture. do you have a feel for what is happening from any of my descriptions?
I mostly get the feel that you don't know what a bunch of these terms mean. Can;'t really get much further from there. Are you basically saying your 2w amp is quite distorted?
ahh, ok, yes it gets too warm and distorted too fast. pup volumes and amp volume low with the LP. sry
Why did you buy two of those amps if they don't sound good?
Quote from: Jake on November 30, 2012, 05:02:14 PM
Why did you buy two of those amps FROM SATAN if they don't sound good?
ftfy.
I dont understand whats going on here ???
but take those two amps back to the store and get a refund
one is a xmas present, just making sure it works...
also, $100 for the initial setup is really cheap. also, I had to start somnewhere.
I really studied the ant mods. I understand about placing an input gain, tone stack, master volume. caps to darken the input, op xformer impedance matching on both sides, how to adjust the bias and shift the tube curve from right to left. too far right=red plate, but the warm distorted sound is over ther. if you shift the center point left and drop the gain it gets clean and crispy...
I bought mine with the express intention of voiding the warranty asap with mods.
so anyway, thx for your help...or not..
so what is happening that my LP maxxes it out almost immediately? high input gain? bad impedance match? high preset master volume, too much tone stack buffer, shit tubes???
Hey Jib, how hot are your pickups? Did you try rolling back the vol on the Paul? I found if I roll the bridge vol down on my SG clone, it sounds a lot better. I run both my fuzzes wide open and it really makes things more articulate. I used to have Dimarzio Super 2's in my Paul and they were brighter, but super fucking hot. I had to drop those pups down like a '49 Mercury. Now I only run super clean pups. I did the Duncan treble-bleed mod to both my guitars too.
Quote from: jibberish on November 30, 2012, 05:21:02 PM
so what is happening that my LP maxxes it out almost immediately? high input gain? bad impedance match? high preset master volume, too much tone stack buffer, shit tubes???
Buying the wrong amp and then using it wrong. Twice. Those knobs on your LP, possibly marked 'volume': turn them down.
looks like a little amp that is designed to be driven to distortion easily. the demos did display some clean tones tho. its sound like it has an input and master volume control? for clean sounds youd want the master higher than the input I am guessing. Your driving the input stage too hard somehow. roll back your guitars volume knob juts a bit as stated above.
try those things. it could be a bad tube, even right out of the box, can you get to the tubes? tap on em with a pencil eraser? do they make noise when you do?
Why do people always forget that the guitar has a volume control?? Try using it, it really does work.
???
Your name is fitting.
alrighty, you guys are on a roll.l I mentioned in the 2nd paragraph of my OP that even with one pickup gone and the vol;ume on the one left barely cracked, it still seems like too fuzzy or sloppy. I took one completely out to see if any weird impedance was happening. nothing sounds nice unless I want the fuzz, then from 9 oclock to all the way up on the amp is about the same.
chovie, this amp only has one volume. I was comparing my dean markley ss combo that does have input and master gains and it sounded like if I set the dean's input up pretty high, then worked the master as the volume..best comparison I have. what you are saying is exactly what is happening.
Now, would you wager a guess as to where the trouble inside is? too hot of input gain? output gain? I do want to learn to mod on this and that's why I just want to start to feel what too much of whatever is, and what it sounds like
so I plugged my tincan Ibanez in again which has lower outputs. I can do any volume[on the guitar. that's what I've been talking about]. plays like a dream. I have nice clean, yet I can get it to bark on attack increase. is this set up for strats or something?
my whole goal is to now try to associate some amp behavior with things that have been discussed, and actually hear what it is to make the association.
the pups in the LP are somehow very different than the Ibanez junkers. seems more than just gain, but idk
If you're set on the Gretas and you want more clean headroom, you'd either need to attenuate with your guitar volume knob or reduce the plate resistor on the first gain stage. Make sure you adjust the cathode resistor so as to keep the stage biased. Also, is the cathode resistor bypassed? You could try removing a cathode bypass capacitor to reduce gain and increase feedback in the stage. Series resistance before the first grid would help as well. You do have a schematic, right? Not to bust your chops, but if you don't understand everything I just said, maybe mods on a tube amp aren't a good idea at this point.
jib I cant help but feel that before you try and mod anything or take Soupkitchens excellent technical advice, you should try and figure out some basics about your guitars and their pickups and such.
I am really confused by alot of the stuff you are saying. For example..you talk about removing one of your les paul pickups to take it out of the equation? doesnt your LP have a pickup selector switch?
If one guitar works fine thru the amp , but another is too hot, doesnt this tell you the problem or difference in tone is probably not in the amplifier?
your amp has two knobs, volume and what else? tone?
have you tried turning down the tone knob? on some older amps (which your amp is apparently styled after) the tone knob can add crunch.
Do a search on Greta Mods. Like the Valve Jr., it's guaranteed that guys are going to be tinkering with it, and documenting their mods online.
Here's a thread, I dunno if anybody actuallly mods it here, TL;DR -- but they talk about clean headroom
http://www.tdpri.com/forum/shock-brothers-diy-amps/354244-greta-mod.html (http://www.tdpri.com/forum/shock-brothers-diy-amps/354244-greta-mod.html)
ok, I have yet to find a schematic which will tell the whole story.
I will also start a new thread when I do some pickup research and have some less chaotic questions to ask vs just exploding like an excited little kid.
Quote from: Lumpy on December 01, 2012, 03:39:18 PM
Do a search on Greta Mods. Like the Valve Jr., it's guaranteed that guys are going to be tinkering with it, and documenting their mods online.
Here's a thread, I dunno if anybody actuallly mods it here, TL;DR -- but they talk about clean headroom
http://www.tdpri.com/forum/shock-brothers-diy-amps/354244-greta-mod.html (http://www.tdpri.com/forum/shock-brothers-diy-amps/354244-greta-mod.html)
Two of the "mods" they talk about to clean the Greta up are—surprise— turning down the volume & tone on the guitar.
to repeat: my LP sounds bad with its volume just cracked, the amp volume just cracked and the tone anywhere. I cnnot turn any down any further and still hear sound.
to repeat: I will study some pick up specs and see what the big difference is between my Ibanez pups. which sound nice(overall tone notwithstanding) and the LP ones
and then I will start a new thread with a more organized and informed topic structure if I even need to by then...
im sitting on an 18 watt and 50 watt Hammond chassis, which I will build some day also. this is the start.
chovie: I jumped my LP selector switch to be always both pups since I use that setting 99% and always hit the switch while playing. so I just straight wired the neck pup to the jack, cut everything else out except the vol and tone for that lone pup. the two pups sort of fucked with each other regarding volumes so I figured, just clean that up to a single pup, no complications.
Sounds like your rewiring could likely be the problem.
Quote from: RacerX on December 02, 2012, 07:49:27 PM
Two of the "mods" they talk about to clean the Greta up are—surprise— turning down the volume & tone on the guitar.
Yeah I just skimmed that thread, because I posted as I was running out the door.
Tube swap, break in the speaker, don't crank the amp/don't expect a lot of volume, roll back your vol. & tone knob.
There's probably going to be some dudes tinkering further, as time goes on.
Profits!
I just... Never expected much out of them.
Quote from: RacerX on December 02, 2012, 09:14:05 PM
Sounds like your rewiring could likely be the problem.
it's possible chief, but I removed a lot of wiring from the live circuit. imagine a single pickup guitar wiring. all grounds are still in place. I really only removed the 4 wire pup selector cable, then put the pup wire in place of the switch return right on the op jack pcb. I even beefed the solder on the ground attachment. there are many LP wiring diagrams out there. it sounds ok through my dean markley. I do know what a screwed up ground sounds like heh..60 cycles is always involved. this is quiet regarding noise.
the problem here is I have absolutely nothing to compare to tubewise. this all may be very normal for whatever sort of design philosophy is in place here.
I also have no sense of the fineness of the range of controls and playing dynamics it takes to ride the sweet spot correctly. not being a highly skilled player probably is hurting me there too. no feel. i'm typing with oven mitts.
but I seriously want to slay this whole tube amp dragon and be competent enough to really start having fun in a productive way (blowing stuff up is always fun..but...)
I have now read about breaking in the speaker, the tubes being swapped...the peeps say it makes a difference. could be an additive thing, where everything that needs tweaking and everything I am not doing right adds up to garbage.
I will keep looking for a schematic. if anyone stumbles across one, hook me up please. there are pics with the cover off I have seen..
I will play one of them a lot to break in the speaker, maybe get some shmansy tubes. at least those models are cheapo tubes. even the good ones. i'll get whatever the tweakers seem to like best if I do.
there really is no point in having everyone guessing what exactly the single volume knob controls without messing with the amp themselves. my guess is that the input gain is preset and that is a master.. wonder if I guessed right lol, but the schematic is the answers.
Quote from: SunnO))) on December 02, 2012, 10:58:02 PM
I just... Never expected much out of them.
Indeed. You're supposed to set it on your desktop. It's like 2 feet from your head. It looks like a radio. It has a mini-plug input for your iPod. It's something to fiddle around on.
Still, you should be able to get a clean tone.
I have to rein myself in...this thing has a line out for running a slave..and a line in for an ipod...sounds like an effects loop to me , and now I would have to say, a master volume makes more sense than an input volume with a dimed master gain for playing an aux input, which should be past the preamp stage since it is line level, not hi impedance guitar level...