Wonderland/JM100 build

Post by **pompeiisneaks** » Fri Apr 21, 2017 4:42 pm

martin manning wrote: ↑Fri Apr 21, 2017 4:27 pm This was done above.

could you clarify what 'this' is

norburybrook · Post by **norburybrook** » Fri Apr 21, 2017 4:43 pm

Sorted.

it was in fact the other 100r resistor that had blown too. I was probably getting 100r from the new 100R on the other side when I was checking it. it wasn't until I lifted it and checked it was dead.

phew!!!

Right then.

where were we? I think I'm going for longest thread of the year here

someone did say a while back it was a bit quiet in here.........

So with the 100k in the voltage divider things are a lot better.

I might try jelle's suggestion of 180k-68k i'm sure that would be louder, it might be too much though, but as I'm here iron in hand it would be churlish not to give it a go for the sake of the community.

Marcus

Post by **pompeiisneaks** » Fri Apr 21, 2017 4:49 pm

norburybrook wrote:Sorted.

it was in fact the other 100r resistor that had blown too. I was probably getting 100r from the new 100R on the other side when I was checking it. it wasn't until I lifted it and checked it was dead.

phew!!!

Right then.

where were we? I think I'm going for longest thread of the year here someone did say a while back it was a bit quiet in here.........

So with the 100k in the voltage divider things are a lot better.

I might try jelle's suggestion of 180k-68k i'm sure that would be louder, it might be too much though, but as I'm here iron in hand it would be churlish not to give it a go for the sake of the community.

Marcus

excellent. Let us know how it sounds.

Sent from my LG-V521 using Tapatalk

erwin_ve · Post by **erwin_ve** » Fri Apr 21, 2017 5:06 pm

Nice to see what members here come up with to troubleshoot!
Is actually a good learning experience

Marcus: besides the voltages/ resistor choices etc, can you make some soundsamples when done?

martin manning · Post by **martin manning** » Fri Apr 21, 2017 5:20 pm

norburybrook wrote: ↑Fri Apr 21, 2017 4:43 pmit was in fact the other 100r resistor that had blown too. I was probably getting 100r from the new 100R on the other side when I was checking it. it wasn't until I lifted it and checked it was dead.

I thought you had checked both sides when you had the PT leads disconnected. As I said above, you would see ~50R to ground with the PT leads connected and both resistors at 100R.

jelle · Post by **jelle** » Fri Apr 21, 2017 5:57 pm

Glad you got it sorted.

norburybrook · Post by **norburybrook** » Fri Apr 21, 2017 6:09 pm

ha who was asking about jelle? here he is ;D

I tried the 180k -68k voltage divider and if the amp had no reverb I'd say its great but I didn't like what it did to the fine balance of the reverb/clean sound. (Actually if it didn't have reverb yo would need this anyway!!)

So at the moment I'm at 1M and a 121k I had lying around.

Thanks everyone..it's been a journey......

now my favourite part...building the cab....NOT

Marcus

Post by **pompeiisneaks** » Fri Apr 21, 2017 6:59 pm

norburybrook wrote:ha who was asking about jelle? here he is ;D

I tried the 180k -68k voltage divider and if the amp had no reverb I'd say its great but I didn't like what it did to the fine balance of the reverb/clean sound. (Actually if it didn't have reverb yo would need this anyway!!)

So at the moment I'm at 1M and a 121k I had lying around.

Thanks everyone..it's been a journey......

now my favourite part...building the cab....NOT

Marcus

I teased him on fb, so he came here

Sent from my HTC 10 using Tapatalk

norburybrook · Post by **norburybrook** » Fri Apr 21, 2017 7:05 pm

ah that was you

your secret is out now......

Marcus

Krinkle · Post by **Krinkle** » Fri Apr 21, 2017 7:28 pm

pompeiisneaks wrote: ↑Fri Apr 21, 2017 6:59 pm
norburybrook wrote:ha who was asking about jelle? here he is ;D
Marcus
I teased him on fb, so he came here

Sent from my HTC 10 using Tapatalk

What FB page is that? Sounds like a fun place to go visit!

Post by **pompeiisneaks** » Fri Apr 21, 2017 8:05 pm

I'm in several facebook groups, tube guitar amplifier builders, etc, I think that's the one he's on. I have like 4 or 5 that are tube related.

Tube Amplifier Repair and Diagnosis
Tube Amplifier Mods
Vacuum tube amplifier.
Guitar Tube Amp Talk
Tube Guitar Amp Builders (said earlier)
and due to me being a big vox nerd: VOX Amps

and yes you found me, I'm pompeiisneaks on almost everything (I kinda hate the name, it was a band I was in ages ago, name came from a bassist that was in the band for like 3 months and bailed) but it's always available, so it's become my moniker. I'm also FrenchieFilms youtube channel where I do amp videos of my builds. https://www.youtube.com/c/FrenchieFilms

I should stop threadjacking now and get back to your amp

Yes please send final sound examples, I'm very curious!

~Phil

martin manning · Post by **martin manning** » Fri Apr 21, 2017 9:47 pm

FB is a very poor platform for this sort of thing IMO.

hywelg · Post by **hywelg** » Fri Apr 21, 2017 11:01 pm

norburybrook wrote: ↑Fri Apr 21, 2017 6:09 pm ha who was asking about jelle? here he is ;D

I tried the 180k -68k voltage divider and if the amp had no reverb I'd say its great but I didn't like what it did to the fine balance of the reverb/clean sound. (Actually if it didn't have reverb yo would need this anyway!!)

So at the moment I'm at 1M and a 121k I had lying around.

Thanks everyone..it's been a journey......

now my favourite part...building the cab....NOT

Marcus

I know you said at the outset you were going with a 1x12, but if you'd like an unfinished 2x12 shell I have two that are surplus to requirements. I'm in Nottingham

Got details about them here

http://www.thefretboard.co.uk/discussio ... ale#latest

norburybrook · Post by **norburybrook** » Sat Apr 22, 2017 8:52 am

thanks I have one of these cabs already with two vintage Celestion G12-65's in. It's a great cab. I need a 1x12 though as I've no small cabs at the moment as I sold them with my amps.

Good price by the way and actually if you use parcel2go it's not expensive to ship one of these in the UK.

Marcus

norburybrook · Post by **norburybrook** » Sat Apr 22, 2017 9:04 am

martin manning wrote: ↑Fri Apr 21, 2017 9:47 pm FB is a very poor platform for this sort of thing IMO.

I agree Martin, I don't think I'll be heading back there too soon for this kind of thing. There's some very knowledgeable people on that FB group but it can quickly descend into the usual internet nonsense. It reminded me of the worst of internet forums. TAG is a place that is generally both helpful and supportive and a nice place to hang out, long may it remain.

Anyway, since we're talking about the amp builders FB page, there was quite a lot of discussion there from the big boys(Fuch's Egnator etc) about the whole voltage divider values and the circuit in general. Some interesting points were raised, mainly:

the 1M-68k values. From the photos of the JM amp I wouldn't bet my house that those values are correct, I can't see clearly the banding on the resistors as they look like they've got 5 or 6 bands and they're hard to see. I'm not full conversant with how a voltage divider works so couldn't comment. I did try with 180k-68k and there was a lot more usable gain but the reverb wasn't as good.

Also the master volume is really a return level and is completely useless as it needs to be on full to work properly.

any thoughts on this?

Marcus

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