Electronics > Projects, Designs, and Technical Stuff

analogue delay

(1/6) > >>

jazzalex:
Hello all,

I have been working a lot with audio equipment and for certain reasons I need to apply an analogue delay to an audio signal. In terms of musical performance with my guitar a Roland Space echo works great ( http://www.rolandmusik.de/produkte/RE-20/index.php ), however, regarding my lab experiment it exhibits unacceptable drawbacks (supports not more than line level / does not support full audio bandwidth up to 20 kHz).

So, what I essentially need is an analogue (really not digital) device that adjustably delays my input audio signal of 5 Vpp by up to 250 ms. In the sound engineering domain nobody can help anymore -- maybe in the EE-world ?

Any pointer appreciated,
thanks in advance

Alex 


IanB:
I don't know what's inside the Space Echo, but if you want to remain in the analogue domain I think you need to use something old and traditional like a tape loop. You put the recording and replay heads a certain distance apart on a closed loop of tape and run the tape at different speeds to get different delays.

Otherwise, since the speed of light is 300 000 km/s you are going to need a length of wire 75 000 km long to provide a 250 ms propagation delay...

wkb:

--- Quote from: IanB on March 22, 2012, 09:51:28 pm ---
Otherwise, since the speed of light is 300 000 km/s you are going to need a length of wire 75 000 km long to provide a 250 ms propagation delay...

--- End quote ---

A 'bit'  more, 3E8 m/s is the speed of light in vacuum.  In a coax it is something like 0.7c or so  ???

T4P:
I initially thought of PT2399 but it's analog style only works up to 5kHz , beyond that all digital craziness sets in but i believe that's just a hunk o' crap .
I see PT2399's in reverb/echo/delay commercial things everywhere .
One warning though , original dip PT2399's can be had for 30cents per piece in 100 off quantities but pray hard that you can find a SOIC package .

jazzalex:

--- Quote from: IanB on March 22, 2012, 09:51:28 pm ---I don't know what's inside the Space Echo, but if you want to remain in the analogue domain I think you need to use something old and traditional like a tape loop. You put the recording and replay heads a certain distance apart on a closed loop of tape and run the tape at different speeds to get different delays.

Otherwise, since the speed of light is 300 000 km/s you are going to need a length of wire 75 000 km long to provide a 250 ms propagation delay...

--- End quote ---

Actually the space echo is a "handy" modern representation of such older devices (the old one's name was also "Space Echo"). So theoretically it's great apart from some additional low-pass filtering and the line level limitation. I might check other approaches, however, the 75 000 km cable might not fit into my office ;-)

Thanks, best

Alex

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version