DIY Metasonix TS Modules!

tablebeast · Post by **tablebeast** » Tue Jul 10, 2012 11:01 am

Wow, I just want to thank Eric for posting the schematics for the TS series of rack modules. For those that don't know these were some of Erics first things sold as Metasonix over a decade ago. They were all fancy full size rack units, were LONG ago discontinued, and now impossible to find these days.

I have built the basic building block tube circuits posted by Eric on Ken Stone's Modular Synth page over the years and always loved the results. Now I can build my own honest to goodness TS modules! I will be doing mine a bit different by using an Akai/ Roberts tube reel to reel amplifier chassis and transformers as donors. This keeps costs to a minimum and the donor amps are easy to work on and very high quality. If you want to see the schematics for yourself go here and click on the "Vacuum Tubes" tab.

http://www.cgs.synth.net/

For more info on my mods go here

http://xfmr.blogspot.com

Thank you so much Eric! You are a continuing inspiration to my tube projects!

decaying.sine · Post by **decaying.sine** » Tue Jul 10, 2012 11:24 am

Are you wiring point to point with a turret board or vero or did you make a PCB?

zerosum · Post by **zerosum** » Tue Jul 10, 2012 12:41 pm

For more info on my mods go here

http://xfmr.blogspot.com

COOL!

bcomnes · Post by **bcomnes** » Tue Jul 10, 2012 1:42 pm

at the risk of being redundant - these pics were posted here a while back - my DIY TS21 "tumor refilled halo" can be viewed here http://www.flickr.com/photos/matrixsynt ... 354036818/

the name is an anagram from "hellfire modulator"

It's built in an old lab test chassis, that's how I got the cool round hole in front

it's point to point, was not that hard if you have tube amp hackery skills, but beware there are lethal voltages and currents inside so don't blame me if you turn into a crisp piece of bacon

Eric liked it but gave me shit about my soldering skills

and there are also sound samples at posted here as well from last december viewtopic.php?t=48874&highlight=ts21

I want to do the TS22 Filter next before I die - been saying that for a while

metasonix · Post by **metasonix** » Wed Jul 11, 2012 3:59 pm

tablebeast wrote:For more info on my mods go here

http://xfmr.blogspot.com

Thank you so much Eric! You are a continuing inspiration to my tube projects!

You're welcome! I should thank you, for being a hardcore DIYer who isn't afraid of plate voltages.

It's good to see you getting some use out of old Magnecord recording electronics. Vintage-audio people hate those things, because they aren't as good as Ampex yet extremely commonplace. (Magnecord transports are even worse, as you've seen. Ampex and Revox are practically the only 1950s tape recorder brands that have a good reputation today.) Ditto for old PA amplifiers. None of them are "collectible", except maybe the McIntosh commercial models.

tablebeast · Post by **tablebeast** » Thu Jul 12, 2012 2:32 am

decaying.sine wrote:Are you wiring point to point with a turret board or vero or did you make a PCB?

The Akai / Roberts units have these tag boards that I reuse. They aren't the best things in the world, but usually clean up pretty good and build a circuit very well. If I was building from scratch I think I would do straight point to point, but the layout of these Akai chassis has a very specific design. I've made all kinds of stuff in these donor chassis. I am going to try to fit all three TS circuits, each in one module, in one large carrying case made from the old tape machine box! Here are some pics showing the before, during, and after pics of one of my projects.

andrewF · Post by **andrewF** » Thu Jul 12, 2012 2:34 am

fucking NICE!!!!

tablebeast · Post by **tablebeast** » Thu Jul 12, 2012 3:11 am

It's good to see you getting some use out of old Magnecord recording electronics. Vintage-audio people hate those things, because they aren't as good as Ampex yet extremely commonplace. (Magnecord transports are even worse, as you've seen. Ampex and Revox are practically the only 1950s tape recorder brands that have a good reputation today.) Ditto for old PA amplifiers. None of them are "collectible", except maybe the McIntosh commercial models.

I LOVE the Magnecords! They have great transformers. Those inputs are massive and can handle just about any signal I've ever thrown at it! The transports are crap compared to modern technology, but the AMPS are great once tweaked out! I see my re-birthing of the electronics sections into useful and interesting studio tools is doing the gear a great service even though some folks would scoff at 'ruining' old decks. As for PAs, clearly I like the Bogen stuff. They have great "fender-cheap" transformers that have a unique sound that always seem to turn out great for guitar. My first projects were mostly Bogens because they were tough to fuck up! These days I am always on the lookout for old tape machine electronics and would even like to get my hands on some vinyl cutting amps if I can find some cheap Presto or Rek-o-Kut unit.

Post by **Kent** » Thu Jul 12, 2012 5:02 am

Those are gorgeous

I like your rather secure wire-wrapping. Once soldered, they ain't goin' nowhere.

tablebeast · Post by **tablebeast** » Thu Jul 12, 2012 11:02 am

at the risk of being redundant - these pics were posted here a while back - my DIY TS21 "tumor refilled halo" can be viewed here

Not redundant at all! Very cool. I think the soldering looks pretty good for a hobbyist and the only way to improve is to just build more stuff. SO, just keep at it and you'll get better. I like the case you're using, reworking something like that is totally my style, do you have any other synth modules?

decaying.sine · Post by **decaying.sine** » Thu Jul 12, 2012 11:10 am

Amazing work. The wiring looks great. Those tag boards are great, and the wrap around wiring is

Moog$FooL$ · Post by **Moog$FooL$** » Thu Jul 12, 2012 11:40 am

wow... really liked your blog!!!

must be easier to come across that old gear in the USA or i guess ebay.

in boring old Canada there just isn't that much of it.

tablebeast · Post by **tablebeast** » Fri Jul 13, 2012 6:54 pm

must be easier to come across that old gear in the USA or i guess ebay. in boring old Canada there just isn't that much of it.

Most of it is from ebay. The average PA amp can be had for under $100 shipped. Just the other day I saw a Bogen CHB-35A (one of my favorite PA amps to covert), go for $49! I was nice and I think complete with tubes. Anyway, there are all kinds of deals for under a hundred bucks. Spend another $30-$50 in parts and you've got an amp that blows away all this modern crap, and gets as many looks as a classic car at shows! Everyone has a seen a Fender or Marshall, but how many Bogen J330s have you ever seen? I've built octal 'Bassman' circuits in those chassis that blow away the original Fenders that the designs came from!

In a town like Vancouver you should be able to find some stuff on Craigslist. Even if you had to put your own ad up looking for old tube PAs, signals tracers, test equipment, radio station gear, etc I'm sure you'd find something. I stumble upon stuff myself at flea markets in my little town, so the stuff is out there. HAM radio events are great places to find the weirdest stuff. Often the stuff the HAM guys want the least is the best for my mod purposes anyway. That old military communications "Signal Corps" stuff always has SUPER high quality parts in it, so try calling military surplus places in Washington State. In the end all I can say is that there is still PLENTY of cool stuff out there, all over the place, you just have to hunt for it!

metasonix · Post by **metasonix** » Fri Jul 13, 2012 9:32 pm

Moog$FooL$ wrote:in boring old Canada there just isn't that much of it.

I would beg to differ, you just have to be more aggressive and clever about finding it. Get friendly with old ham-radio operators and antique-radio collectors, scour garage sales, watch the newspapers for estate sales. PA equipment is just as common in Canada as in the US.

I know one of the top radio collectors in California. He's quite good at scouring Palo Alto and surrounding environs for old gear. One of his favorite tricks: stake out the local recycling center. Some days they get nothing, but once in a while a truckload of old electronics shows up to be dumped. The widows don't want to be reminded of their late husband's junk-collecting hobby, so they're usually in a hurry to get rid of it.

equalpyramid · Post by **equalpyramid** » Fri Jul 13, 2012 9:56 pm

Is there anything in particular to look out for? I've been checking some and a lot of them are caked in dust and rust. Most of them say "It powers up, but no way of checking if it works", is that enough for a decent DIY project?

tablebeast · Post by **tablebeast** » Fri Jul 13, 2012 10:33 pm

equalpyramid wrote:Is there anything in particular to look out for? I've been checking some and a lot of them are caked in dust and rust. Most of them say "It powers up, but no way of checking if it works", is that enough for a decent DIY project?

Dust and crust cleans off with a elbow grease. Rust on transformers is no big deal. In fact rust on a transformer can actually be your friend, no shit. Sellers don't know this so if it IS rusty scratch your chin and say, "I don't knowwwww..." and you'll get it cheap.

9 times out of 10 the transformers still work and that is the important part. In my projects at least I ditch nearly all the original circuit and wiring so the iron and case are the only thing I really reuse. And of course the tubes. Contrary to popular tech scammers most of these old tubes, especially the preamp tubes, have most of their lives left. Rectifier tubes go out next and the ones that last the least amount of time are the power tubes, but most of them STILL work just fine. And don't believe the hype about new tubes being 'just as good or BETTER' than the old stuff. That is horse shit. I will take some old used RCA or GE tubes over the fanciest new piece of Chinese or Russian shit. On the other end of the scale don't waste money on fancy European tubes either. Mullards and Telefunkens are great and all, but again I'll take a used RCA for 1/10 the price of one of those guys. If you REALLY want some Mullards older Bogen amps and some Heathkit test equipment is stuffed with them.

once in a while a truckload of old electronics shows up to be dumped.

Another idea would be to stay in contact with a metal scrapyard. I have scored a few amps for 10 cents a pound before!

Moog$FooL$ · Post by **Moog$FooL$** » Sat Jul 14, 2012 12:01 pm

Woah!! thanx for the info. fellas.

just so happens that (just yesterday, in fact) i came across an old GE home console from roughly the mid 60's. i'll post a pic & info. in a separate thread later.

clearly we need a "found tube(s) & trnx-'s" emoticon(s)!!

tablebeast · Post by **tablebeast** » Sat Jul 14, 2012 9:02 pm

just so happens that (just yesterday, in fact) i came across an old GE home console from roughly the mid 60's. i'll post a pic & info. in a separate thread later.

You got to watch out for those old consoles as a lot fo them used designs with no power transformer as well, mostly later, cheaper designs. What you want to look for is at least two transformers in anything that drives a speaker and at least one transformer for anything working at line level. They vary in size depending on their capacity, so smaller amps+ smaller transformers obviously. SOME designs are tricky, like the Wollensak T-1500 reel to reel deck. It uses a power transformer for the preamp tubes ONLY, the power tubes are 12 volt battery types and it uses an AC voltage doubler circuit to drive its B+. Translation, it SUCKS for a power amp transformer by itself, but works great for a preamp or guitar effects pedal, etc. The first scores you get will be hit or miss, but over time you will know what to look for.

Moog$FooL$ · Post by **Moog$FooL$** » Sat Jul 14, 2012 10:35 pm

tableb. you bet i follow you.

it was one very large piece of "furniture".

viewtopic.php?p=870012#870012

metasonix · Post by **metasonix** » Sun Jul 15, 2012 12:15 am

tablebeast wrote:Dust and crust cleans off with a elbow grease. Rust on transformers is no big deal. In fact rust on a transformer can actually be your friend, no shit. Sellers don't know this so if it IS rusty scratch your chin and say, "I don't knowwwww..." and you'll get it cheap.

Correct

9 times out of 10 the transformers still work and that is the important part. In my projects at least I ditch nearly all the original circuit and wiring so the iron and case are the only thing I really reuse. And of course the tubes. Contrary to popular tech scammers most of these old tubes, especially the preamp tubes, have most of their lives left. Rectifier tubes go out next and the ones that last the least amount of time are the power tubes, but most of them STILL work just fine.

Yep

And don't believe the hype about new tubes being 'just as good or BETTER' than the old stuff. That is horse shit. I will take some old used RCA or GE tubes over the fanciest new piece of Chinese or Russian shit. On the other end of the scale don't waste money on fancy European tubes either. Mullards and Telefunkens are great and all, but again I'll take a used RCA for 1/10 the price of one of those guys. If you REALLY want some Mullards older Bogen amps and some Heathkit test equipment is stuffed with them.

This snobbery over Telefunken/Mullard/whatever is excessive, in my opinion. Both firms made 12AX7s/ECC83s to a good standard of quality, especially for high-fidelity audio use. They are often original equipment in hi-fi equipment from the 1955-65 era. Being mass-produced, they were simply a little better made than American types. In case you didn't know, there was a premium American version called 12AD7--people tend to ignore 12AD7s because they've been lectured for 20 years to look for Telefunken and Mullard tubes. Just as good. (Yes, I've personally tested them all.)

And yes, the new tubes being made today usually have inferior cathode materials, giving a shorter lifetime. I'm convinced the Chinese factories do this deliberately, to improve the aftermarket.

tablebeast · Post by **tablebeast** » Wed Jul 25, 2012 1:55 pm

In case you didn't know, there was a premium American version called 12AD7

The Akai Roberts monoblocks came stock with a Japanese-made NEC 12AD7. They nearly always test like new and sound AMAZING. In fact I like all the NEC made tubes, but I rarely see them outside of these Akai amps.

fyzygy · Post by **fyzygy** » Thu Aug 28, 2014 10:54 pm

Ditto, a big thanks to Eric for sharing his proven designs.

I have successfully built a number of the smaller DIY modules listed at the Audio Synthesis via Vacuum Tubes page. (EF86 filters, 2D21 noise generator, 6BM8 waveform clipper ... not to mention a version of Eric's vacuum tube wah pedal).

However, when it comes to the TS22 schematic - the pentode filterbank - I'm confused. Aren't 4n7 and 4700pF one and the same value? In which case filter bands #1 and #4 appear to be identical ( superfluous filter?).

Filter. Ca, Cb

1. 4700P, 2200P
2. 1N, 4700P
3. 2N2, 1N
4. 4N7, 2N2

If these values are correct (and 4n7=4700pF), then (a) 1 and 4 are identical filters, the purpose of which configuration eludes me; and (b) the four bands are designed to have different response curves, given these inconsistent value ratios; band 2 seems inversely weighted to the other three in that Ca:Cb is 1:4.7 rather than, say, 2.2:1...

http://www.cgs.synth.net/tube/ts22.html

Any help at all would be appreciated.

metasonix · Post by **metasonix** » Fri Aug 29, 2014 2:28 am

fyzygy wrote:Aren't 4n7 and 4700pF one and the same value?

"4n7" should be 47,000 pF.

the four bands are designed to have different response curves, given these inconsistent value ratios; band 2 seems inversely weighted to the other three in that Ca:Cb is 1:4.7 rather than, say, 2.2:1...

Yeah, so?

fyzygy · Post by **fyzygy** » Fri Aug 29, 2014 6:11 am

okay, cool. thanks.

tablebeast · Post by **tablebeast** » Fri Aug 29, 2014 3:14 pm

not to mention a version of Eric's vacuum tube wah pedal

Is there a schematic available for this? Sounds like a cool project! A friend of mine recently got a Mutron wah to run his vocals through and it is harsh and noisy. Maybe this would work better? ANyway, a schem would be awesome!

MUFF WIGGLER

MUFF WIGGLER

DIY Metasonix TS Modules!

DIY Metasonix TS Modules!

Re: DIY Metasonix TS Modules!