using an old tape delay on tascam 388

[suonoacaso]

hi, i'm pretty new to recording....
i have this old tube tape echo, an echolette E51, it plays very good in front of a guitar amp, but if try to put it in the effect loop of my reel-to-reel TASCAM 388 it's barely audible if i push both effect sends and returns level on maximun. and of course, it distorts.
It's a matter of impedance or what?
Any suggestion?
thanks

 

[Steenamaroo]

Hi,
Are you using TS cabling throughout?

If the e51 is designed for instrument in/instrument out then the 388 will probably be able to overpower it, and the e51 will probably return a signal weaker than the 388 wants.
That would make sense if your result is too quiet but distorted.
You'll have to gain-stage the best you can to compensate.
Ie. Don't go overboard with the send, but keep the e51 and return as loud as you can.
You could even try monitor straight off the e51 (into an amp) to make sure you're not pushing it too hard.

If that doesn't work, maybe you'd have better luck pulling the effects send back (to avoid distortion) then just returning to a new channel, mic input w/ low gain, or a -10 line input if the board offers that?
IDK, worth a try.

Seems like it shouldn't be a problem though...Check the cabling is all TS first.

If the 388 offers RCA and TRS/TS for send or return, try each of them.
I've a feeling RCA might operate at -10.

 

[ecc83]

Found a schematic for the NG 51, I doubt the I/O is much different for the "E"?

Yes, impedance AND level issues. Had it all the time with those pesky valves! The NG's output is on DIN sockets but I bet the E 51 is fed the same, from the very high 470k resistors. Solution? A buffer I would bet a simple FET op amp such as the TLO72* would be fine and the output level could then be several VOLTS rms.

The input problem is simpler, pot in a tin. If you wanted to preserve guitar usage use 1meg Ohm log pots but the cable to the echo unit needs to be short, no more than about a foot/18inches. No guitar? Make the pot 10K Ohms and then the output cable can be several feet.

I realize that this all needs some technical knowledge and metal bashing/soldering skills but that's the name of the game if you want to mess with WAAAAAY out of date valve equipment. I bet that EM84 "magic eye" level indicator is borked? Good luck finding another!

*Could fit a valve circuit inside, a cathode follower. Use a 12AU7 or 12AT7.

Dave.

 

[mdainsd]

Don't worry about finding the EL84 tube (assuming you even need it or want it), a cursory check on eBay shows about 800 of them for sale at prices from 5 bucks apiece.

 

[ecc83]

Don't worry about finding the EL84 tube (assuming you even need it or want it), a cursory check on eBay shows about 800 of them for sale at prices from 5 bucks apiece.

Was E "L" 84 a typo here or did you put it in a search? The EL84 pentode is of course plentiful and cheap. The E "M" 84 may not be.

BTW. If OP's unit DOES have the pentode in it he WILL need one since it will be the Bias Oscillator. The circuit I posted shows an push-pull BO but cheap ole' tape kit often used a single pentode and it doubled up as the replay output stage. Cannot do that for an echo unit, need record and play same time.

Dave.

 

[mdainsd]

Yeah a typo. The EM84 brought back hundreds of returns on a search, EL84 brought back thousands.

Now if the damned 6386 tubes were that plentiful I would be set

 

[ecc83]

Yeah a typo. The EM84 brought back hundreds of returns on a search, EL84 brought back thousands.

Now if the damned 6386 tubes were that plentiful I would be set

Cool! Have one for me. (I wish!)

Dave.

 

[skywaveTDR]

Forget about all these fancy solutions. Just take a Aux send out into the echo and bring it back into one of the line in and you can use gain on the mixer section to bring the level up if needed. If that does not work then get some more compatible equipment.

 

[ecc83]

Forget about all these fancy solutions. Just take a Aux send out into the echo and bring it back into one of the line in and you can use gain on the mixer section to bring the level up if needed. If that does not work then get some more compatible equipment.

If he does that, according to the schematic I found he will be running a signal through 470k into 10k. That is attenuation of 54dB. He will have little left but noise.

Dave.