Whats on your amp workbench?

Amp tinkerers and people who aren't afraid of 700 volts or so in here....

Moderators: Slowy, Capt. Black

Aquila Rossa
Vintage Post Junkie
Vintage Post Junkie
Posts: 5025
meble-kuchenne.warszawa.pl
Joined: Wed Jan 14, 2009 5:53 pm
Location: Auckland
Has liked: 183 times
Been liked: 118 times

Re: Whats on your amp workbench?

Post by Aquila Rossa »

P.S. I bought this amp for a good price thinking a clone would be a good platform for trying mods on. Now I have the Freyette Power Station I do not need a master volume, while as for tone; I just want it to sound like a great Plexi really.
What's a great Plexi though? There are a few main versions of the JMP 1987 curcuit and several variations of them. Knowing the right blend of them to get the Plexi sound is the trick. That's what I have been up to with this amp (next is to try a 4700pf bright cap on the treble channel, plus try different taps and values for the NFB).

User avatar
robthemac
Vintage Post Junkie
Vintage Post Junkie
Posts: 8981
Joined: Sun Apr 28, 2019 3:47 pm
Has liked: 1134 times
Been liked: 1462 times

Re: Whats on your amp workbench?

Post by robthemac »

Aquila Rossa wrote: Mon Jun 03, 2024 3:20 pm What's a great Plexi though?
Different tones for different ears! The 18W 1974 and 36W 1962 and the definitive Plexis for me. Just playing a 1974 in a 1x12 Creamback combo and was sounding glorious. Loud without being unmanageable at home.

The 2061 was supposedly only 2w more, but seemed to have much more headroom and I just couldn't get it into its sweet spot very often.

The few times I've managed to play the 1974 or 2061 through a closed 4x12 were epic.
Jops wrote: Sun Sep 18, 2022 7:46 am Spring is the comic sans of reverbs anyway.

Aquila Rossa
Vintage Post Junkie
Vintage Post Junkie
Posts: 5025
Joined: Wed Jan 14, 2009 5:53 pm
Location: Auckland
Has liked: 183 times
Been liked: 118 times

Re: Whats on your amp workbench?

Post by Aquila Rossa »

robthemac wrote: Mon Jun 03, 2024 4:05 pm
Aquila Rossa wrote: Mon Jun 03, 2024 3:20 pm What's a great Plexi though?
Different tones for different ears! The 18W 1974 and 36W 1962 and the definitive Plexis for me. Just playing a 1974 in a 1x12 Creamback combo and was sounding glorious. Loud without being unmanageable at home.

The 2061 was supposedly only 2w more, but seemed to have much more headroom and I just couldn't get it into its sweet spot very often.

The few times I've managed to play the 1974 or 2061 through a closed 4x12 were epic.
Plexi is synonymous with the 1960s Superlead amps, but you're right; those early Marshall combo amps were Plexi too, because they have the plexigas control panel.

User avatar
robthemac
Vintage Post Junkie
Vintage Post Junkie
Posts: 8981
Joined: Sun Apr 28, 2019 3:47 pm
Has liked: 1134 times
Been liked: 1462 times

Re: Whats on your amp workbench?

Post by robthemac »

Aquila Rossa wrote: Wed Jun 05, 2024 4:42 pm
robthemac wrote: Mon Jun 03, 2024 4:05 pm
Aquila Rossa wrote: Mon Jun 03, 2024 3:20 pm What's a great Plexi though?
Different tones for different ears! The 18W 1974 and 36W 1962 and the definitive Plexis for me. Just playing a 1974 in a 1x12 Creamback combo and was sounding glorious. Loud without being unmanageable at home.

The 2061 was supposedly only 2w more, but seemed to have much more headroom and I just couldn't get it into its sweet spot very often.

The few times I've managed to play the 1974 or 2061 through a closed 4x12 were epic.
Plexi is synonymous with the 1960s Superlead amps, but you're right; those early Marshall combo amps were Plexi too, because they have the plexigas control panel.
Huh, weird. I always considered everything from JTM45 through to the Superlead/Superbass to be "Plexi".
Jops wrote: Sun Sep 18, 2022 7:46 am Spring is the comic sans of reverbs anyway.

User avatar
Bg
Site Admin
Posts: 43540
Joined: Fri Sep 05, 2003 12:13 am
Location: Auckland
Has liked: 2284 times
Been liked: 4040 times

Re: Whats on your amp workbench?

Post by Bg »

As some farcebook friends have seen, the missus wanted a Bluetooth speaker but hated the look. So I said I can build one into an old radio for her.

One visit to Temu later and it’s working surprisingly well.

2x3watts one speaker is the original rola.

Took bits out but left the tuning bits and the transformer for some reassuring weight.

Bluetooth and rechargeable battery.

Wife points well earned. 50s wireless that was buggered gets a new lease of life and a discreet rear control panel. Drilling Bakelite is not much fun but it worked out well - chain drilling then dremel.

IMG_1417.jpeg
IMG_1417.jpeg (399.42 KiB) Viewed 679 times
So, is that low alcohol or no alcohol at all? mmmm, no alcohol, do you want to try it? Noooooooooo.

User avatar
jeremyb
Chorus of Organs
Posts: 42360
Joined: Sat Dec 06, 2008 9:03 am
Has liked: 8057 times
Been liked: 4299 times

Re: Whats on your amp workbench?

Post by jeremyb »

So cool Beeg!!
Slowy wrote: That's the problem; everything rewarding is just such hard work. Regret takes much less effort.

User avatar
Bg
Site Admin
Posts: 43540
Joined: Fri Sep 05, 2003 12:13 am
Location: Auckland
Has liked: 2284 times
Been liked: 4040 times

Re: Whats on your amp workbench?

Post by Bg »

turned out really well, I'll need to take a pic of the back to show how the blue tooth panel looks.

It sounds surprisingly good but I'm sure there are better options out there.

If I have tin ears, my missus has lead ears. So she's happy ;)
So, is that low alcohol or no alcohol at all? mmmm, no alcohol, do you want to try it? Noooooooooo.

User avatar
Jay
Vintage Post Junkie
Vintage Post Junkie
Posts: 7938
Joined: Sat Sep 25, 2010 9:35 pm
Has liked: 1681 times
Been liked: 1336 times

Re: Whats on your amp workbench?

Post by Jay »

Needs gut shots
When faced with quality, I recognise it every time.

User avatar
Bg
Site Admin
Posts: 43540
Joined: Fri Sep 05, 2003 12:13 am
Location: Auckland
Has liked: 2284 times
Been liked: 4040 times

Re: Whats on your amp workbench?

Post by Bg »

Oh no it doesn't... I chopped lots of stuff out to make way for bits going in :D
Was planning on gutting it completely but it would have weighed nothing, I figured a nice bit of transformer would prevent cats from knocking it off.

Small bluetooth board thing set into the back, a battery holder and battery, a new speaker and old speaker wiring. Bosh.

Chain drilling and filing Bakelite for the control panel - about an hour, got to go easy on that stuff, have cracked it beyond redemption in a previous life.
So, is that low alcohol or no alcohol at all? mmmm, no alcohol, do you want to try it? Noooooooooo.

User avatar
WellyBlues
Vintage Post Junkie
Vintage Post Junkie
Posts: 3961
Joined: Mon Jun 16, 2008 8:01 pm
Location: Welly
Has liked: 542 times
Been liked: 358 times

Re: Whats on your amp workbench?

Post by WellyBlues »

Bg wrote: Fri Jun 14, 2024 8:06 pm As some farcebook friends have seen, the missus wanted a Bluetooth speaker but hated the look. So I said I can build one into an old radio for her.

One visit to Temu later and it’s working surprisingly well.

2x3watts one speaker is the original rola.

Took bits out but left the tuning bits and the transformer for some reassuring weight.

Bluetooth and rechargeable battery.

Wife points well earned. 50s wireless that was buggered gets a new lease of life and a discreet rear control panel. Drilling Bakelite is not much fun but it worked out well - chain drilling then dremel.


IMG_1417.jpeg
Taking orders for more? Put me at the top of the list.
Slowy wrote: Ultimately though, guitars are like women. On paper there's not much difference but only a few can make you happy.
Ray Wylie Hubbard wrote: And the days that I keep my gratitude higher than my expectations Well, I have really good days

User avatar
NippleWrestler
Vintage Post Junkie
Vintage Post Junkie
Posts: 3034
Joined: Sat Jan 02, 2016 5:05 pm
Has liked: 81 times
Been liked: 1124 times

Re: Whats on your amp workbench?

Post by NippleWrestler »

Did you get the Bluetooth module from Temu? If so was it easy to hook up to power, speakers, etc?

User avatar
TmcB
I may have a problem
Posts: 7833
Joined: Fri Aug 22, 2008 12:17 pm
Location: Kapiti
Has liked: 693 times
Been liked: 596 times

Re: Whats on your amp workbench?

Post by TmcB »

Ugh, customers Deluxe Reverb looks like it needs a new OT.

Came in with one dead power tube and a bunch of microphonic tubes.

Got new tubes that sorted out microphonics but I heard some weird crackle at higher volumes on certain notes.

Traced the noise to the power tube socket (can tap the tube to replicate) then to a blue wire. Thought it was a CEO solder joint but tapping the wire replicated the noise…followed the wire to the OT and on the outside of the chassis, if you tap the wire it makes the noise.

I think there’s a break in the wire somewhere from the OT to the socket that’s causing it to disconnect on vibration, which explains the dead power tube and the best solution is to replace the OT altogether.
GrantB wrote:Tony, your taste is, as always, very refined. Or as HG would say, "bloody awful".
Family Music Store - http://familymusic.co.nz

User avatar
MikeC
Vintage Post Junkie
Vintage Post Junkie
Posts: 3092
Joined: Fri Sep 12, 2003 5:43 pm
Location: Red Beach, Auckland
Has liked: 1383 times
Been liked: 933 times

Re: Whats on your amp workbench?

Post by MikeC »

TmcB wrote: Sat Jun 15, 2024 8:35 am Ugh, customers Deluxe Reverb looks like it needs a new OT.

Came in with one dead power tube and a bunch of microphonic tubes.

Got new tubes that sorted out microphonics but I heard some weird crackle at higher volumes on certain notes.

Traced the noise to the power tube socket (can tap the tube to replicate) then to a blue wire. Thought it was a CEO solder joint but tapping the wire replicated the noise…followed the wire to the OT and on the outside of the chassis, if you tap the wire it makes the noise.

I think there’s a break in the wire somewhere from the OT to the socket that’s causing it to disconnect on vibration, which explains the dead power tube and the best solution is to replace the OT altogether.
I had a similar amp with a similar symptom - it was the choke.
Whakanuia o mea kei a koe

User avatar
Bg
Site Admin
Posts: 43540
Joined: Fri Sep 05, 2003 12:13 am
Location: Auckland
Has liked: 2284 times
Been liked: 4040 times

Re: Whats on your amp workbench?

Post by Bg »

NippleWrestler wrote: Sat Jun 15, 2024 7:16 am Did you get the Bluetooth module from Temu? If so was it easy to hook up to power, speakers, etc?
Easy as pie, I’ll take a pic of the back and send a link to the module.
So, is that low alcohol or no alcohol at all? mmmm, no alcohol, do you want to try it? Noooooooooo.

User avatar
NippleWrestler
Vintage Post Junkie
Vintage Post Junkie
Posts: 3034
Joined: Sat Jan 02, 2016 5:05 pm
Has liked: 81 times
Been liked: 1124 times

Re: Whats on your amp workbench?

Post by NippleWrestler »

Bg wrote: Sat Jun 15, 2024 12:34 pm
NippleWrestler wrote: Sat Jun 15, 2024 7:16 am Did you get the Bluetooth module from Temu? If so was it easy to hook up to power, speakers, etc?
Easy as pie, I’ll take a pic of the back and send a link to the module.
Now i'm slightly more awake, presumably there's an amplifier required also.

Post Reply