My implementation of the Cordell Distortion Analyser

[EUVL]

I am posting this in the Solid State Forum as there used to be a couple of permanent threads for Bob Cordell. So I thought it is more appropriate here than elsewhere.

A couple of years ago I was attracted to Bob’s DIY distortion analyser by a htread at the Pass forum :

distortion analyzer recomendations?

Someone has actually made one :

distortion analyzer recomendations?

But that link no longer works. So I could perhaps post the photos here without getting into trouble.


Patrick

[EUVL]

Another attempt was posted here, but I did not manage to find pictures of the finished article :

Circuits Online - Forum - Show your projects! Part 6.


P.

[EUVL]

I always wanted one, but they were too expensive here even 2nd hand. An HP339 typically costs more than 400 Euros, and it also does not have balanced IN/OUT, which I want. Plus no service manual, probably many obsolete parts with no spares, …., that gave me enough excuse to build one myself.

As always with DIY projects, it cost just the same as a bought one in the end if not more, was a LOT of work, but also quite a bit of fun. Would have been more if it would produce music as well.

So here I am sharing with you some pictures of the finished article.

[jan.didden]

Originally Posted by EUVL

Another attempt was posted here, but I did not manage to find pictures of the finished article :

Circuits Online - Forum - Show your projects! Part 6.


P.

Nice! Brings back memories from when I build this unit, many, many moons ago. Alas, I no longer have this unit, but it worked flawlessly. A great design by a great designer!

At the time, I got the boards from Bob. BTW, where did you get the case? Looks quite professional.

jan didden

[EUVL]

A look inside :




P.

[EUVL]

PCBs & the somewhat challenging switches :


P.

[EUVL]

The new components -- balanced In / OUT :


P.

[EUVL]

We are particularly proud of the battery case, as the thinnest wall behind the battery holder is only 1.5mm thin, and it is solid wood, not ply.

We do, however, want to redo the wooden end plates and the battery case, as the wood grains do not show up very well after dying them black. Minor cosmetic issues.


P.

[EUVL]

Last but not least, my tribute to the designer for a great design and detailed description. Many thanks Bob for sharing this with us.


Patrick

[EUVL]

Jan,

> Alas, I no longer have this unit, but it worked flawlessly. A great design by a great designer!

Could not agree more.

> BTW, where did you get the case?

It was a length of electrical trunking rescued from the scrapyard. Did making wiring a pain because of restricted access from the top, but saved me 100 Euros for a commercial enclosure. And for sure one of a kind. This particular extrusion that I have is no longer available, but this is something similar :

OBO BETTERMANN - LFS. GEK-A device installation trunking aluminium systems, 80 mm cover

The end plates and the battery case were milled from solid beech wood (Buche Leimholz).

The lettering was done by Lazertran :

Lazertran Waterslide Decal transfer paper for use with photocopiers

And I did use the baked technique.


Patrick