Pretty sure I damaged my amp with my diy boost pedal.. Help fixing plz..

[Steel Curtain]

Hello all,

         A friend of mine ordered up a treble boost pedal recently, which inspired me to build one of my own. Well, I basically used a LPB schematic and added a 47uf cap to the emitter and plugged it in. I ended up cranking it, not being fully aware of the unbelievably high amount of boost this thing would kick out. It was on the breadboard and I didn't wire in a switch or bypass... After tweaking a little, and pounding the front end of my Fender Blues Jr. for a half hour or so, I disconnected the pedal and plugged my guitar directly into my amp and noticed immediately that the treble frequencies were diminished a little. It didn't sound as sweet as it normally does. I also had to turn the amp volume up higher than normal to get to my normal playing level. The treble to bass balance has definitely been altered by my boost pedal.

                  I'm pretty sure i damaged something, I'm hoping it's just the preamp tubes and I didn't damage a component on the input.

Anyone have any idea what I may have done here? What could I have damaged? Could I have damaged a resistor or cap on the input? Or could I have hit the preamp tubes way to hard and damaged them?

Thanks all..

[boogietone]

Though electronics damage is always possible, this might me a case of simple ear fatigue. Going from a dimed lpb into a tube preamp to just the preamp could easily result in a volume drop while the fletcher Munson effect would affect how you perceive the tone. Tube amps are pretty forgiving. Check again when your ears have recovered.

[bwanasonic]

Second the vote for ear fatigue. Always a good lesson that what you're hearing isn't always hardware. 

[psychedelicfish]

When your ears are exposed temporarily to a potentially damaging level of sound, a chemical is produced which reduces your ear's sensitivity for a short period to reduce the chance of further permanent damage. This could be what's happening with you and your amp, if you were sitting in a small room and/or close to the amp at the time.

[duck_arse]

When your ears are exposed temporarily to a potentially damaging level of sound, a chemical is produced which reduces your ear's sensitivity for a short period to reduce the chance of further permanent damage.

this chemical is called beer.

[wavley]

Yeah, I'm gonna vote for ear fatigue too.

[Mark Hammer]

It's not a chemical that is produced, so much as a chemical NOT being produced.  Nerve cells need time to recover and produce the transmitter substances that permit them to send messages to each other.

It is exactly analogous to suddenly being exposed to an intense light (e.g., you forgot to pull your welder's mask down soon enough after positioning the welding rod).  The persistent afterimage is a result of those retinal cells not being able to respond to anything for a while after.  The amount of time it takes you to see clearly after that is the amount of time it takes for a sufficient number of light receptors to rebuild their stock of relevant chemicals in their membranes, and also restore the balance of ions inside and outside of the membrane.  Here's a nice little animation explaining things: http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.html

[Quackzed]

just for arguments sake, it could be that you slammed an already 'over the hill' preamp tube too hard and for too long... still, not a problem other than finding then replacing the curprit. tubes need replacing sooner or later...

[Steel Curtain]

Well,

         I plugged in my guitar and fired it up again this morning. And it appears to sound just fine! I couldn't help but notice that the ringing in my ears was louder than usual when i was trying to sleep last night. Ear fatigue? I wonder if this means I should limit the time I spend swapping out components and fine tuning my circuits. I feel kind of silly for posting this now.. Hey, I learned something!

         I like the welder analogy, Wavley. I'm a welder! UA LOCAL777...

Thanks guys!

[aron]

Yep, the good old TOO LOUD problem. Protect your ears when you can.

[pinkjimiphoton]

you could plug a 9 volt battery directly into the input with a 1/4" plug and do ZERO damage to it bro, so nope, not the lpb.

you describe ear fatigue, and tube amps both. the longer you play it, the more it's tone will change. bias shifts all over the place as the voltage from the wall goes up and down, humidity affects speaker response, all kindsa stuff.

you couldn't damage your amp. i doubt the caps are rated for less than 400 volts, and you can probably drive line levels (70 volts or so) into a 12ax7 grid without killing it.

rock on.

[PRR]

> the ringing in my ears was louder than usual

You should not have "usual" ringing.

ANY ringing means you should turn it down. Also limit exposure time.

I can no longer hear much above 1KHz, or understand speech across the room. It is VERY difficult.

[Quackzed]

agreed. hearing loss of high end and ringing in the ears is no joke. be very carefull with your hearing. its not just that you cant hear high notes on a piano or guitar, its that you cant hear in a crowd that people talk to you and you smile and nod and dont really know what they just said because its lost in the background buzz, annoying maddening piercing whistles in your ears that NEVER stop. ever.

[pinkjimiphoton]

watt?

seriously. listen to paul. i'm not as bad as paul... yet. i can still hear to about 12k 45 years in, so i'm lucky.
i have a hard time hearing stuff across a room too, if there's background noise, forget it.

i ended up with https://en.wikipedia.org/wiki/M%C3%A9ni%C3%A8re%27s_disease meniere's disease after 4 decades exposure to ridiculously loud noises. i used to play thru multiple 100 watter stacks back in the day, often dimed. i was NOT quiet.

now, everyday, i have to eat sh*t called meclizine to stop the vertigo, and take ativan to ease the nausea from it. 2-3 times a day sometimes.

some times it works. some times it doesn't.

some times i end up on the ground somewhere for a couple hours, until it finally passes, unable to walk or function, unable to tell direction, unable to open my eyes even cuz of the confusing jumble of sh*t moving from my ears sending the wrong signals to my brain.

the only cure is surgically cutting the otic nerve. stops the nausea. leaves ya stone-cold deaf.


all cuz i wanted to rock out with my c*ck out, and play stupid loud.

don't do it. don't end up like me. it ain't worth it. was so bad back in 2005 i had to retire from live performance.
i've lost 40% of the hearing in my right ear, 60% in my left. it's not worth it. i'm only 51, and am already half deaf.

if you need to play that loud, wear ear protection.

or better yet, use the resources on this forum to learn how to get YOUR tone, at whatever volume is sane.

not to be a buzzkill... but theres not much worse fate for a musician than to eventually know you'll never hear music again.

peace.

sorry for the hijack.