Recently got a 18w OT from SteveUK, what to build?

brooom

Nice, will look into it

ICBM

Punches give the best results, but they’re very expensive to buy if you only need to do one hole occasionally. Definitely worth seeing if you can borrow one - aluminium won’t chew it up.

Modulus_Amps

brooom said:

I'm looking more at the "bass circuit" end of the spectrum but that does sound nice, thanks for the video.

I'll give that a go, I'll probably need to adjust feedback and maybe the power rail nodes a bit.

That's why I said the black flag amp, as it has the bass response. IMO the Black Flag JTM is better than the classic JTM45, even though on paper they are so similar.

If you are going for high B+ watch your screen voltages with EL84's

McToot

Modulus_Amps said:

I built an 18w hot rodded M style amp, fixed bias and thought it was the best 18w amp I have built so far. 

You can hear it cranked up in this video, but it does amazing clean tones too
https://www.youtube.com/watch?v=_A4MjfH1Vn8&t=423s

Wow. That thing sounds absolutely epic. Love it. Great work. 

brooom

Modulus_Amps said:

brooom said:

I'm looking more at the "bass circuit" end of the spectrum but that does sound nice, thanks for the video.

I'll give that a go, I'll probably need to adjust feedback and maybe the power rail nodes a bit.

That's why I said the black flag amp, as it has the bass response. IMO the Black Flag JTM is better than the classic JTM45, even though on paper they are so similar.

If you are going for high B+ watch your screen voltages with EL84's

Will check the schematic today. I think my 275-0-275 power transfomer even with a gz34 should be in the low 400s.

I'm also thinking 6V6s fized biased, rather than el84s.

John_A

ICBM said:

Punches give the best results, but they’re very expensive to buy if you only need to do one hole occasionally. Definitely worth seeing if you can borrow one - aluminium won’t chew it up.

These work well and aren't expensive

https://www.zoro.co.uk/shop/hand-tools/punches-wad-and-hole/q-max-sheet-metal-cutter-hole-punch-20mm-diameter-round/p/ZT1001894X?utm_source=google&utm_medium=cpc&utm_campaign=dsa-generic&utm_content=hand-tools&targetid=dsa-955248742767&gclid=Cj0KCQjw8eOLBhC1ARIsAOzx5cFAvleuNJdRA4wmzkpFHQFw7IS6JdU_j5Qkxr3n_iLolz1ILd8voCoaAuLTEALw_wcB

pluckbuddy

Thanks @John_A think I'll probably get one of these

ICBM

John_A said:

These work well and aren't expensive

https://www.zoro.co.uk/shop/hand-tools/punches-wad-and-hole/q-max-sheet-metal-cutter-hole-punch-20mm-diameter-round/p/ZT1001894X

That's a pretty good price for one of those, even a basic fairly small diameter one.

John_A

pluckbuddy said:

Thanks @John_A think I'll probably get one of these

Check the size. That was just a random link

pluckbuddy

John_A said:

pluckbuddy said:

Thanks @John_A think I'll probably get one of these

Check the size. That was just a random link

Will do. Was thinking the same thing. I may bail in any case on adding reverb. My chassis already has 3 preamp holes which will be enough for a mini bassman type build without any additional hole cutting.

Fundamentally I'm very lazy and my project will likely not see the light of day for some months at the soonest. @brooom please let us know how you get on

brooom

took me some time to get around to my tweed champ... so I'm fairly certain I'll also be moving slow. But if all goes well I'll start ordering parts next week as well as doing the initial layout.