Mason wrote:I have a novice-style amp question!My main amp for a short while has been a Garnet Jammer. It's kind of peculiar and there isn't a ton of info about it floating around. Besides this circuit.1. Is there a real cursory overview someone could give me based on the circuit topology? Just like "oh it's kind of like x Fender amp with y thing different about it"2. Mainly what has me trippin is the interplay between the two preamps (like w/ the higher-gain input). I would love to understand what's going on there. That is what I am doing this post about.3. I dug up a picture of the back of my own personal amp, which is at the practice space right now, and I'm noticing for the first time a Solo Pre-Set control (upper right)? What on earth is that. Amp has a two preamp gain controls and a master volume on the front, what else is even left for that knob to be.Thank you!Did you buy that online a few months ago..for like 500? You bastard

llllllllllllllllllllllll wrote:Where can I use a volt meter to make sure the charge is drained from this 50s GA-40 amp? It doesn t have 12ax7 in the preamp so I can t use the first pin in v1. I need to change out the speaker in this bitch and the screws and nuts to pull the chassis are located inside the chassis because why wouldn t they be?http://imgur.com/ozCPOF3http://imgur.com/GA60Z9Wassuming your meter can handle the voltage: clamp your return lead to the chassis, put one hand in your pocket and take the measurements right off the caps. (I hold the hot lead with some wooden clamps/tongs that I drilled a hole in, because it makes me feel good. if you have good leads this is unnecessary and maybe more dangerous? )I feel better this way because circuit topologies vary and sometimes the problem you're trying to fix might cause a bad reading

Tommy wrote:VaticanShotglass wrote:Can't sleep so here's a question I'm just going to rip from a Gearpage thread that no one responded to as I have exactly the same concern:As we know the vintage fuzzes (or vintage circuits in new fuzzes) don't play nice with a buffer in front.My plan is to set up an overdrive pedal chain and a fuzz pedal chain.Can anyone speak to the buffer + fuzzes thing with the LS-2?The pedal (LS-2) has input and output jacks, and send/return jacks for loops A and B. The incoming signal is buffered, then split three ways: to the output mixer/buffer, to loop A send and loop B send. If left empty, the send/return jack in each loop are connected internally, to simply pass the signal along. Each loop has a level control, located after the return jack. The return signals then join the main bypass signal in the output mixer/buffer, and is then sent out through the output jack. https://www.thegearpage.net/board/index ... z.2037693/In my case I want to run a Rat in parallel with an EQD soundshank, which is a great buzzaround clone.So what's the question here? I have an LS-2 I use parallel like you describe. The LS-2 is buffered and affects a Fuzz Face/Rangemaster/etc the same way other buffered pedals do. The only difference here is that you have control over signal amount. If you don't like what a buffered pedal does before your fuzz pedal of choice now, you're not going to like what the LS-2 does to it without using some sort of impedance correcting device (maybe Radial) in the loop.A Rat sounds fine with a buffered pedal in front of it. Is the Soundshank the problem child here?Sorry I missed this reply! Yes, the Sound Shank is the piece in question. I love the way it sounds but it just need lots more bass. I think it gets finicky with a buffer. I usually use a Rat, but thinking that having a bit of both would be perfect (like double tracking a part with two very different sounds). Separately, they are two of my favorite dirt sounds. I like the big gritty slab of dirt, which remains articulate, from the Rat but I'd like more fuzzy sizzle (pick any goofy tone words) sitting on top of it. I'm just thinking of a more complex sound without multi-amping at a gazillion decibels.

llllllllllllllllllllllll wrote:Where can I use a volt meter to make sure the charge is drained from this 50s GA-40 amp? It doesn t have 12ax7 in the preamp so I can t use the first pin in v1.A GA-40 doesnt have a 12AX7, but that 5879 tube does have a plate (pin , and that's what pin 1 (and 6) are on a 12AX7. You can drain the caps from there. The reason that Skip mentions that trick on the podcast, assuming thats where you heard it, is because theres a plate resistor between the pin and the reservoir caps, thereby allowing for a slow drain from the pin with no pops and sparks. Its effectively the same as a "snuffer stick" sold by Weber, StewMac, etc. You would use a wire with alligator clips or other such lead to drain the caps from the preamp pins, though, not a voltmeter.The voltmeter can be used to check if there's any voltage in the amp. In your case you could use that one on pin 8 of the preamp tube because the voltage there shouldnt ever be as high at 250. Also you can easily get a voltmeter for $20 that'll read up to 1000VDC

W.L.Weller wrote:Dr. Balls typed "pin 8" above, but the forum software automatically turns an 8 and a ) into a Well....it IS the coolest pin...

llllllllllllllllllllllll wrote:Yep, that podcast is what I was referring to! I knew the voltimeter was just to check the charge, just wasn t sure where to put it. The amp hasn t been turned on in weeks and I was getting a reading of 0 everywhere which kind of made me nervous. It s dumb but I would have preferred to watch it go down so I could be sure I was measuring it correctly.I get you. A true positive in this case is better than a true negative as you can be for sure. What you're looking for is voltage on the reservoir caps. In any tube amp these are gonna be electrolytic, polarized caps in the form of large cylinders. They will have one side (the negative) tied to ground (the chassis) and the other, positive side tied to the power rail. You want to test for voltage between the positive side and the chassis. In that amp, when its on, that will be ~300VDC. When its off that voltage will slowly dissipate, and in some caps that happens quicker than others. Some will hold a voltage for a minute, some for days.In this pic of a GA-40 you can see those two big brown/orange guys and those are reservoir caps:

Oh....i should also mention that in any amp all of the reservoir caps are on a chain. Draining the caps from one node of that chain, or pins 1 or 4 of the first 12AX7, drains the whole chain. If one of those caps shows zero volts, the whole chain is drained.

Dr Tony Balls wrote:llllllllllllllllllllllll wrote:Where can I use a volt meter to make sure the charge is drained from this 50s GA-40 amp? It doesn t have 12ax7 in the preamp so I can t use the first pin in v1.A GA-40 doesnt have a 12AX7, but that 5879 tube does have a plate (pin , and that's what pin 1 (and 6) are on a 12AX7. You can drain the caps from there. The reason that Skip mentions that trick on the podcast, assuming thats where you heard it, is because theres a plate resistor between the pin and the reservoir caps, thereby allowing for a slow drain from the pin with no pops and sparks. Its effectively the same as a "snuffer stick" sold by Weber, StewMac, etc. You would use a wire with alligator clips or other such lead to drain the caps from the preamp pins, though, not a voltmeter.The voltmeter can be used to check if there's any voltage in the amp. In your case you could use that one on pin 8 of the preamp tube because the voltage there shouldnt ever be as high at 250. Also you can easily get a voltmeter for $20 that'll read up to 1000VDCYep, that podcast is what I was referring to! I knew the voltimeter was just to check the charge, just wasn t sure where to put it. The amp hasn t been turned on in weeks and I was getting a reading of 0 everywhere which kind of made me nervous. It s dumb but I would have preferred to watch it go down so I could be sure I was measuring it correctly. I wonder how many sniffer sticks Stew Max sold because of that episode, even if he was going on about how it wasn t necessary. One at least!

Dr Tony Balls wrote:llllllllllllllllllllllll wrote:The voltmeter can be used to check if there's any voltage in the amp. In your case you could use that one on pin 8 of the preamp tube because the voltage there shouldnt ever be as high at 250. Also you can easily get a voltmeter for $20 that'll read up to 1000VDCthe $20 meter worry for me is the cheap insulation on the leads - often sitting on the shelf for years. PVC is PVC mind you.Here's some that aren't too expensive and fit UL standard https://www.grainger.com/product/MILWAU ... uded-6JHW4

Dr. Balls typed pin 8 above, but the forum software automatically turns an 8 and a ) into a