wrote:

Got this tape echo machine at work. Got tubes. Old. Tape runs and it was a fresh job for me. I see it has bias and audio mixing with it. It passes signal but does not echo. I think the tape is simply bad.

Anyway, it has no pinch roller. The tap goes about 1430 degrees around it though. That is apparently enough.

However O think this arraingement would cause faster tape deterioration due to more bending. Isn't the straightest path the best ? (for the tape itself of course)

It is kept under tension by a springed idler. There are no tape pads. It has a magnetic erase head between a fixed and spring loaded idler or tensioner. Lke a turing tape guide. The capstan is way over on the right side. There are like five heads, electronic heads not the PM erase head.


** You just MIGHT be describing Charlie Watkins' famous little horror - the "WEM Copycat" first released in 1958.

http://manningsmusicals.co.uk/wp-con...ms-007-800.jpg

A truly horrible machine that just barely worked, it's output was riddled with AC hum, tape noise (from the permanent magnet erase) and serious wow & flutter plus amplitude modualtions.

Charlie was too cheap to admit it needed a pinch roller.

Modern 1/4 inch tape normally refuses to run on a WEM Copycat as the surface friction is just too low. You could try fitting a shrink plastic sleeve over the capstan if you like.


I am actually disappointed by the thing not hav ing a speed control. What, they didn't have eddy current motors in the 1940s ?


** Some very cheap echos used simple, DC brush motors and others had two speeds - but the first machines to feature decent, BLDC variable speed motors were made by Roland of Japan. Models include the RE101, RE201, RE301 and deluxe versions were the RE501 & SRE555.

A fairly large BLDC motor branded "Pioneer" provided direct capstan drive and continuously variable speed range of about 5:1 with varying compensation applied to EQ circuits as tape speed changed to keep the response flat. There was also an NE570N compander IC to reduce tape noise to quite low levels.

The erase head was ferrite cored and the record and play heads had stainless steel face plates that simply never wore out.

Nice machines, fixable and well worth fixing even today.


..... Phil