The reason ac30s are so hard on tubes is that amp was originally designed around the Mullard el84s. Modern tubes like JJs and EH el84s are not as robust as the OG Mullards. The trick on making them happy is get rid of the 100ohm screen grid resistors and replace them with 1k metal film 2watt resistors. Cool the bias down a bit with a 68ohm cathode resistor or a 75ohm. Which ever one that keeps the output tube dissipation between 100-120 % total dissipation on the 4 output valves. Just a little trade secret.
My super twin reverb would run fine on 4 tubes with the outside two pulled but I kinda like the sextet of 6l6’s making it scream so clean 🤘🏽. I really gotta get that monster running again damn 6C10 are going for nearly 170£ that’s more that the rest of the tubes combined, even with an up charge for matching the 6l6s
this is just good advice I don't know if I would call it a hack. it's a good idea to have a spare matched set of power tubes tested ahead of time because the tube market is super sketchy and suppliers often try and pass off mismatched sets as matched. but that's a whole other youtube video
I know you said you liked the Marshall DSL 100 Watt head and the way it was put together or something like that. have been flirtin with gettin one of these, how do you like this amp?
@@DaveBarlowGuitar Awesom idea, thank you Davey! I know where one is on consignment for cheap. I remember when you built up your 4x12 shop cab for cheap, JOB DONE!
yeah and make sure your not standing on a cement floor in the basement in your socks LOL put your shoes on and maybe stand on a piece of dry plywood or something because 4 to 500 volts DC can cut through a pair of flipflops or better yet if you don't know what "draining the caps" means don't even mess with it take it to an amp tech.
I've heard if you have a 4xEL84 amp with a speaker load of 16 ohms if you pull two tubes you need to set the impedance selector to 8 ohms. This will correct the speaker load. but I would want to double-check that with an actual amp technician
Glad your back Davey! Rock N Roll across the pond!
You know it!
The reason ac30s are so hard on tubes is that amp was originally designed around the Mullard el84s. Modern tubes like JJs and EH el84s are not as robust as the OG Mullards. The trick on making them happy is get rid of the 100ohm screen grid resistors and replace them with 1k metal film 2watt resistors. Cool the bias down a bit with a 68ohm cathode resistor or a 75ohm. Which ever one that keeps the output tube dissipation between 100-120 % total dissipation on the 4 output valves. Just a little trade secret.
Oooohhhhh looking forward to the next vid, nice one Mr Barlow🤘🤘🤘🤘🤘🤘🤘🤘🤘🤘🤘🤘🤘🤘🤘
More to come!
@@DaveBarlowGuitar and looking forward Sir, your audience is captivated
Might work to get you through a gig. Pulling tubes the OT sees a different load impedance. Need to then run it off a lower ohm OT tap
Good advice buddy
My super twin reverb would run fine on 4 tubes with the outside two pulled but I kinda like the sextet of 6l6’s making it scream so clean 🤘🏽.
I really gotta get that monster running again damn 6C10 are going for nearly 170£ that’s more that the rest of the tubes combined, even with an up charge for matching the 6l6s
Thanks 👍
Gotta love a twin .
this is just good advice I don't know if I would call it a hack. it's a good idea to have a spare matched set of power tubes tested ahead of time because the tube market is super sketchy and suppliers often try and pass off mismatched sets as matched. but that's a whole other youtube video
I know you said you liked the Marshall DSL 100 Watt head and the way it was put together or something like that. have been flirtin with gettin one of these, how do you like this amp?
DSL 40, I would pull one out of a combo and put it in a head and plug a 4x12 in, Job Done.
@@DaveBarlowGuitar Awesom idea, thank you Davey! I know where one is on consignment for cheap. I remember when you built up your 4x12 shop cab for cheap, JOB DONE!
One hand in ya pocket if ya plan on reaching into a tube amp.
old school LOL
yeah and make sure your not standing on a cement floor in the basement in your socks LOL put your shoes on and maybe stand on a piece of dry plywood or something because 4 to 500 volts DC can cut through a pair of flipflops or better yet if you don't know what "draining the caps" means don't even mess with it take it to an amp tech.
Reduces the power by half don't it...? Better than losing the gig 👍
I've heard if you have a 4xEL84 amp with a speaker load of 16 ohms if you pull two tubes you need to set the impedance selector to 8 ohms. This will correct the speaker load. but I would want to double-check that with an actual amp technician