need some help with space echo input impedance....

[bobster]

hi guys ,
im looking for some advice to improve my old evans tape echo [ basically a roland space echo clone ]
im not overly clever electrically but not too bad at soldering , have made a fuzz face/ tonebender / booster and can do basic service jobs on my valve amp so please bear this in mind  

im finding when i plug my guitar in the sound isnt that good. kind of like playing through a PA speaker or something but duller......
ive seached around the web and found this quote from a gretsch forum which may be the solution i need-

The adjustable bias trap might need to be adjusted. Its an inductor on the board with a screwdriver slot on top. Be careful...they're brittle. Also, the input impedance is way too low for a guitar. You can add a JFET follower to the input jack and improve the tone immensely. It'll become clean and twangy instead of dull and mid-rangey. Plugging into a stock Space Echo instrument input is the same as using a 5K volume pot on your guitar.

can anyone please guide me in how to install the 'jfet follower to the input jack ' this quote alludes to ?

many thanks as always for any help
regards
bob

[cortezthekiller]

I think this is the forum thread you are referencing:

http://www.gretsch-talk.com/forum/technical-side-things/72499-roland-space-echo-re-201-issues.html

It has a diagram for hooking up the single JFET preamp circuit on the thread if you scroll down. Not too complicated if you've got the parts and know where to hook all the connections to.

I have a roland space echo and read that running a pedal that is buffered when bypassed (ie: any boss pedal) into the unit does the same thing without having to mod it.
When the pedal was plugged into the echo (a boss super overdrive in my case) and bypassed, the sound was way more crisp and full, so perhaps give that a go if you would prefer to keep the unit stock.

[bobster]

thanks dude ,
ive had a breakthrough today.
the echo has mic/line input switches and i usual had it set to the one with least noise and hiss
plus it has output -db settings x 3 and i usually used the middle one which again had less hiss

so today for an experiment i demaged the heads , cleaned them and set to work trying 30 foot long cables / pedals in front of and behind the unit.

turns out that after the clean/demag i can set it to the settings discussed above that would have had excess hiss before and now i get hardly any hiss and a much better signal level and even some nice saturation distortion from the amp when i turn guitar vol up full

stoked!
gonna use this tomorrow on its own [ no pedalboard ]  into a 2203 100 watt marshall with my loud wedding band and will be grinning like a cheshire cat if this thing keeps working like it did tonite
yum