The vintage gear forum, named in honour of the hundreds of people left vintage samick guitars in an estate....

Moderators: Slowy, Capt. Black

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BY el byrdo
#804307
Cheers, my amp is obviously before they decided to put the diagram on. In other news I just tried out the 6/40 through the celestial gold! PHWOAR!, I am in tone heaven!

DOD 280 comp is pretty nice too
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BY GrantB
#804308
That 4/12 looks the biz. What’s the tube assemblage again Bruce?
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BY el byrdo
#804316
Turns out it was already set to 8 ohms. Maybe that's why the holden cab doesn't sound quite as good as it could? the cab is set to 16 ohms. When I bought my Jansen I thought it was a 6/20, which would have been even cooler than a 40.

Another question: When I turn on my amp the tremolo sounds mint, super loud and choppy, but then fades to almost nothing... bad tube?
User avatar
BY jvpp
#804321
Slowy wrote:
jvpp wrote:
H671 wrote:
Have you seen this site?

http://www.ozvalveamps.org/jansen.htm


Yes browsed that site a while ago for a 6/20 diagram. Could not find it there and it does not mention the 4/12.

4-12s are rare. I've only ever seen 2. Consider they were made in 1964, just as full stacks were taking over the world. Poor little fellas never stood a chance.


Spoke to Clarry and he confirms they are rare and hasn't got any diagram. The good thing is he has repaired a couple and says the circuit is very simple.
Will call Simon tomorrow and if no luck I am offering to do the exploratory surgery... Perhaps a dedicated thread is warranted rather than annoying EB?
User avatar
BY Bg
#804331
Just say no, if Simon offers you a 1 megawatt PA with a 789 i/o mixer desk. Stick to your guns.
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BY Danger Mouse
#804334
The problem with this thread, even though it is spelt differently, it keeps making me day dream about joining a slightly different owners club:

Image
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BY Danger Mouse
#804342
Ahead of you on that one, the one in my pic is also an Interceptor R. Not supercharged in this case, but I prefer the colour. Plus it's relatively paltry 480hp is probably still enough for a bit of fun.
User avatar
BY GrantB
#804374
jvpp wrote:
Slowy wrote:
jvpp wrote:
Yes browsed that site a while ago for a 6/20 diagram. Could not find it there and it does not mention the 4/12.

4-12s are rare. I've only ever seen 2. Consider they were made in 1964, just as full stacks were taking over the world. Poor little fellas never stood a chance.


Spoke to Clarry and he confirms they are rare and hasn't got any diagram. The good thing is he has repaired a couple and says the circuit is very simple.
Will call Simon tomorrow and if no luck I am offering to do the exploratory surgery... Perhaps a dedicated thread is warranted rather than annoying EB?


Let us know how you go. I could chat to John G in Hamilton...see if he could help out. He’s reversed engineered some of my booteek stuff before.
User avatar
BY Optical
#804413
Slowy wrote:
bender wrote:
jvpp wrote:Now that i have heard that 4/12 I wouldnt mind getting or making one. Any cicuit diagrams yous guys have?


Yeah, that’s an amp worth cloning! Ask Clarry?

If there is someone who can do it, I'd make my amp available for non invasive mapping. I think it would be a cool project to be involved with. :thumbup:


I'd happily trace this out. I've documented a lot of Gunns and Holdens over the years
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BY Mattallica
#804417
Optical wrote:
Slowy wrote:
bender wrote:
Yeah, that’s an amp worth cloning! Ask Clarry?

If there is someone who can do it, I'd make my amp available for non invasive mapping. I think it would be a cool project to be involved with. :thumbup:


I'd happily trace this out. I've documented a lot of Gunns and Holdens over the years


Is there anything special in a Jansen preamp versus, say a Fender? (Thinking about MTS blackface module options)
User avatar
BY Optical
#804438
Dunno, Ive got two Jansens (or bits of...) but both were trashed when I got them.
There is a very strong chance of them being a fender circuit or something incredibly close to. Usually a bassman or JTM type thing but the transformers are often quite different as they were usually locally made radio/HiFi spec which can change the tone and dynamics a bit. Also 50+ year old capacitors are typically fucked which also change the tone (compared to if it were new), meaning you have to measure the components rather then read the labels to know exactly what's going on.
User avatar
BY calling card
#804441
I've got a Jansen Lil' Dazzler 30 watt solid state thing lurking in my amp archives, circa 1970's. One of my older specimens, may take a photo.
BY tubeswell
#804457
Had a few Jansens over the last 40 years. Still got this renovated 1964 Bassman 50 which I salvaged from a dumpster 3 years ago and fixed up. I managed to re-use most of the mustard caps. (Note the 12V heater wiring)
Attachments
Cab front.jpg
Bassman 50 gutshot.jpg
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BY Bg
#804466
Yeah they're the good ones :) With the beer intakes :)