Matchless Chieftain tone stack

[brewdude]

18watt.com is still around. I am on it in a different window right now.

...Hmnnn, this got me wondering if there was something about the way I access it through a bookmark to search for unread threads. So, I tried to access it through 18watt.com and got a "Forbidden" message. Then I logged out of 18watt and went to sewatt.com and hit the 18watt link. This sent me to the 18watt web site which has login button. I was able to login in the normal way.

I have noticed that there is much less traffic at 18watt.com lately.

[M Fowler]

I quit trying to logon after the site crashed.

Many guys here are familiar with Marshalls so the advice on this website is just as good.

Lite IIB there are a few different versions out there I like this one.

Mark

[Darkbluemurder]

I built an amp based on the handwritten Chieftain schematic that was on Schematic Heaven but without the reverb. I made a few minor modifications:

1. I put the optional 25uf bypass cap on the cathode of V1 on a switch for a gain boost. However, with the boost on you have to turn down the guitar volume for a clean tone.

2. Treble pot is a 250kA with a 0.01uf cap. This provides a greater range.

3. I removed the bright cap over the volume. With the cap the tone was much too glassy, almost icey with single coils.

4. I replaced the cross-line master with a LarMar PPIMV. To me it sounds better at lower volumes, does not affect the effectiveness of the cut control as much and is easier to dial in.

5. I used a 250kA pot with a 5000pf cap as brilliance control. The 500kA specified in the schematic was too difficult to dial in.

6. I used a TAD JTM-45 power transformer, a Marstran JMP-50 output transformer and a MM 20H choke on a JTM-45 chassis. It is currently in a Bluesbreaker combo cabinet with a Jensen Neo and a Jensen Tornado. But it also sounded good in an 18W combo cab with a Celestion Alnico Gold, however I was afraid to push the amp for the fear of blowing the speaker.

I used the amp in my country rock band. Plenty loud and a great pedal platform.

I believe Mark Sampson chose the tone stack since it does not eat as much signal as the FMV tone stack.

A slight disadvantage in the design is that you cannot control in the amp how hard the 2nd gain stage gets hit because there is no gain control in the classical sense. The volume control controls how hard the PI gets hit so it's basically a pre-PI master volume. This means you have to control the amp from the guitar unless you set it for clean tones exclusively.

Cheers Stephan

[dearmond]

I had a Chieftain and it sounded great. I've played Alternative, classic rock, blues and country using only one distortion pedal. The build is unique but it works. The only problem is you go through power tubes. EL34's don't like hanging upside down!

[Darkbluemurder]

The only problem is you go through power tubes. EL34's don't like hanging upside down!

Maybe, but that is not the reason why it likes to eat power tubes. They are simply biased too hot with those 270R individual bias resistors. I upped them to 390R in my build (forgot to mention in my post above), even though 330R would probably sufficient to keep things in check.

[sniffyduke]

I think Sniffyduke a member here used one in a country venue as well.

Yes I used a chief.

If anyone wants tracks from cd, send me an email address.

Great amp. Also Used a Fender tweed on Cd.

Mostly for my rock stu ff I am a classic Clubman fan.
95 era

[M Fowler]

Michael,

love the window treatment is that a thermal pane keeping the heat out or in

[brewdude]

A slight disadvantage in the design is that you cannot control in the amp how hard the 2nd gain stage gets hit because there is no gain control in the classical sense. The volume control controls how hard the PI gets hit so it's basically a pre-PI master volume. This means you have to control the amp from the guitar unless you set it for clean tones exclusively.

Thanks for the response. I was thinking that if you wanted to reduce the signal to the 1st stage you would run the bass and mid at low settings and then add just enough treble to balance it out. I like the idea of using the volume control on the guitar to control the amp.

[brewdude]

I had a Chieftain and it sounded great. I've played Alternative, classic rock, blues and country using only one distortion pedal. The build is unique but it works. The only problem is you go through power tubes. EL34's don't like hanging upside down!

Thanks for the response. Can you elaborate on the effectiveness of the tone controls? Perhaps, describe it's tonal attributes, it's "voice"?

[brewdude]

I think Sniffyduke a member here used one in a country venue as well.

Yes I used a chief.

If anyone wants tracks from cd, send me an email address.

Great amp. Also Used a Fender tweed on Cd.

Mostly for my rock stu ff I am a classic Clubman fan.
95 era

Thanks for the response. What's is the sonic difference between the Chieftain and the Clubman? What's the difference in their individual voices?

[sniffyduke]

The Clubman breaks up eariler. More on like Marshal Plexi
but still keeps a Matchless chime which is whats cool.

Chiefton has that DC30 vibe its a bright amp.
Less breakup. Nice chime though.

Both are great with pedals. They love OCD's by fulltone.
Put a tape Echo with it as well and your in tone heaven.
Chief is also has reverb.

Clubmans in my opinion should not have verb.
Some reason screws with the circuit.

I could send clips via email of both.

Clubman clips are killer.

[sniffyduke]

Michael,

love the window treatment is that a thermal pane keeping the heat out or in

Its from NAMM. limited amp rare. In 1995 it was used to show off hand wiring.

[Zippy]

The only problem is you go through power tubes. EL34's don't like hanging upside down!

I had no issues with EL34 failures when I was gigging a Traynor YGL-3 Mk II combo for all those years...

[Firestorm]

The only problem is you go through power tubes. EL34's don't like hanging upside down!

I had no issues with EL34 failures when I was gigging a Traynor YGL-3 Mk II combo for all those years...

Interesting. Traynor tied the suppressor grids to the bias supply. Maybe that's the recipe for keeping the EL34s alive.

[sniffyduke]

Yes, can run through tubes quick.

I use NOS phillips big bottles, last a little longer.