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Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 9:09 am
by RaymondSunshine
Hey everyone, first post :D

I made the trip up to Whangerei to pick this guy up. After a bit of fiddling its all working - sounds great, very clean and quiet and the tremolo is lovely. Anybody here know anything about this model?

I haven't been able to find anything online and the schematics for the 6twenty I have also include a reverb spring which this obviously doesn't have.
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Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 10:31 am
by hamo
I got nothing to add, but welcome to the forum!

Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 10:35 am
by Anvil Amps Alan
Ask on the Facebook Jansen Amplifiers page. There is a Jansen 6/40 schematic available there which is almost identical.

Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 10:37 am
by GrantB
Lovely! Look how close to the chassis some of the cap leads are! Yikes.

Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 10:37 am
by GrantB
Anvil Amps Alan wrote: Fri Jan 14, 2022 10:35 am Ask on the Facebook Jansen Amplifiers page. There is a Jansen 6/40 schematic available there which is almost identical.
What is the 6 relating ?

Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 10:43 am
by Jake
GrantB wrote: Fri Jan 14, 2022 10:37 am
Anvil Amps Alan wrote: Fri Jan 14, 2022 10:35 am Ask on the Facebook Jansen Amplifiers page. There is a Jansen 6/40 schematic available there which is almost identical.
What is the 6 relating ?
6 tubes twenty/forty watts I think?

Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 10:52 am
by Jay
Nice one. My BiL has the combo version which was serviced by Clarry in Titirangi some years ago. I am sure he has the schematic.

Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 11:21 am
by Anvil Amps Alan
I don't know if Clarry has it. I have it (
from F/B Jansen page) but I can't post it here for some reason. And yes it's 6 valves, 20 watts.

Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 3:23 pm
by Jay
Anvil Amps Alan wrote: Fri Jan 14, 2022 11:21 am I don't know if Clarry has it. I have it (
from F/B Jansen page) but I can't post it here for some reason. And yes it's 6 valves, 20 watts.
Can't find it there. Do you have a link?

Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 3:36 pm
by MogwaiBoy
I have one I have one!...

Image

1966. Needs a service though.

Warmer more refined sound than the (dull in my opinion) Bassman 50's, but still has a bit of that warm Jansen thing in the high end (presence roll off - no Blackface 'Bright' button here folks). Definitely a big organic tone, not modern in the slightest.

The tube bias tremolo is the best I have EVER heard - utterly thick, creamy throb (Jeremy, easy tiger) that absolutely annihilates any Fender blackface "Vibrato". You can watch light dancing back and forth between the powertubes in the back.

Pretty decently loud for 20 watts - 5881's I think mine has. Pedals like a champ. Goodluck with yours and hope you enjoy it :)

PS the only info I have is the preamp tubes are:

V1: 12AX7 Ch1 preamp
V2: 12AX7 Ch2 preamp
V3: 12AX7 trem oscillator and cathode follower (do not use modern Tungsol here)
V4: 12AX7 (or 12AU7) driver and phase splitter

This info was from Ryan here: https://www.nzguitars.com/forum/viewtopic.php?t=24402

Re: Jansen 6Twenty Info

Posted: Fri Jan 14, 2022 6:27 pm
by RectifiedAmps
There's also the little-known 6-thirty as well:
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Re: Jansen 6Twenty Info

Posted: Mon Jan 17, 2022 2:11 pm
by RaymondSunshine
Thanks for the info everybody, I've been playing around with it this weekend and the tremolo is wonderful. Still a bit of work to do but am loving it, even the strange homemade finish is growing on me!

Re: Jansen 6Twenty Info

Posted: Wed Jan 19, 2022 9:32 am
by Anvil Amps Alan
RectifiedAmps wrote: Fri Jan 14, 2022 6:27 pm There's also the little-known 6-thirty as well:

tempImagenGtR7t.gif
I have one on my bench right now. Bias was in excess of 50mA so I had to do my bridge rectified bias mod instead of the singe diode.
Managed to get (-)10v more and got the bias spot on for the plate volts at 40mA.

Re: Jansen 6Twenty Info

Posted: Wed Jan 19, 2022 9:34 am
by GrantB
Nice - did Jansen ever do anything lower powered w reverb and trem?

Re: Jansen 6Twenty Info

Posted: Wed Jan 19, 2022 9:58 am
by Jay
GrantB wrote: Wed Jan 19, 2022 9:34 am Nice - did Jansen ever do anything lower powered w reverb and trem?
They did a 4/12 version with reverb in combo format. Obviously reverb needed some extra valves and bits so it is called a 6/12. With 6 valves one would think it has trem as well but I am not sure.