Aussie tube amps from days long gone...

[Marcel]

Howdy,

Some of you may recall that I built a 2204 clone from an old amp chassis that had I kept in the shed for the past 40 years. Well, in my search for other circuits I have stumbled across the info on the original beast that became my 2204 clone. It was in a former life a ETI Playmaster PM116 giving a very clean 40W using a pair of 6DQ6's

http://www.ozvalveamps.org/playmaster.htm#116

When I got it my amp had been modified to use 6L6's, and after the 2204 rebuild I changed it so that it now uses EL34's. I am seriously looking at rebuilding again back to 6L6's although a full restoration back to original 6DQ6's is not off the cards.



For those who are interested our Aussie amp building hobbyists at the now defunct electronics magazine ETI did venture into wild territory, such as a Tube based 140W monster called the Playmaster 456 - Rocker ... A brute of an amp with nil tone stack, one volume control & some on/off switches.... Just what's needed for those special non-guitar loving neighbours...

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

I'm sure the site has other treasures of Aussie tube history...

[DrNomis_44]

Cheers Marcel, I've actually visited ozvalveamps.org quite a few times in the past, it's a great website as well as a great resource for those wishing to get into DIY guitar amp making, I have always wondered what the ETI Playmaster 456 Rocker amp sounded like, I'm guessing that it must have sounded huge, I seem to remember reading the article with a lot of enthusiasm and if my memory serves me right it had a switch that enabled you to switch off the amp's negative feedback, I also remember that the HT Voltage measured something like 750 V DC or so, pretty scary not to mention very lethal as well.

[Marcel]

A link for Doc.... the SC (Silicon Chip) magazine 12AX7 preamp by Jim Rowe...

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

[DrNomis_44]

Ah, I remember that one Marcel, Jaycar Electronics used to stock the parts kits for the Valve preamp along with the power supply kits, unfortunately Jaycar discontinued the kits a few years ago.


As a point of interest, Valve technology has one big advantage over Solid-State technology, if in the unlikely even an EMP (Electromagnetic Pulse) was triggered, one of the two different technologies would instantly cease to work and the other would carry on working, as it turns out, Valve technology is relatively immune from the damaging effects of an EMP.

[Marcel]

Ah, I remember that one Marcel, Jaycar Electronics used to stock the parts kits for the Valve preamp along with the power supply kits, unfortunately Jaycar discontinued the kits a few years ago.


As a point of interest, Valve technology has one big advantage over Solid-State technology, if in the unlikely even an EMP (Electromagnetic Pulse) was triggered, one of the two different technologies would instantly cease to work and the other would carry on working, as it turns out, Valve technology is relatively immune from the damaging effects of an EMP.

Which is the exact reason that Russian military aircraft up until the break up of the USSR all used only tubes in their electronics.... it was by (military) choice and not the lack of availability of solid state devices....

[DrNomis_44]

I did a quick internet search for the ETI 456 Rocker and managed to find a pdf of the full construction article, here's a link to it if you're interested Marcel:

http://messui.polygonal-moogle.com/v...ti_1980_05.pdf


While looking through the list of amp brands on the ozvalveamps.net website, I came across one Amp brand that brought back some memories, the amp brand was Vadis, I distinctly remember doing some servicing work on a Vadis "Extended Range" Guitar Combo Amp for a good friend of mine while I was working in my dad's workshop as an apprentice fitter and turner during the late 90's, it needed a fair bit of work to get it working properly, the power supply originally used a 5U4GB Rectifier and had been modded to use some Solid State Rectifier diodes, the original power transformer had been replaced too.

[corsair]

I still use an old ELFA Bass amp; it's an oldie but a goodie and stacks up against all but boutique and really high-end amps! My main stage amp for much of my career was a Holden 100 combo, made in Christchurch, NZ; I like the old things very much indeed!

[dave.king1]

I have very fond memories of my Lenard SGB 150, damn those 8x12 speakers moved some air

[Marcel]

I seem to remember someone else did a 8x12 cabinet. I think it was a special from Marshall. Can't remember who it was for and I don't think many were made.

A Marshal full stack of 2x4x12 which is pretty much the same thing,.. when cranked .... = very loud!!!!

I get enough noise from my 2x12's ... lol

[dave.king1]

The Lenard had 2x4 ported cabinets and the 8x12 Marshall "fridge" cabinet was a prototype for Pete Townsend