Dr ZEE Workshop FISHER K-10 Spacexpander Spring Reverb Lab Test

[DoctorRazzArea4]

Your guitar sounds very asian, how did u do that? Are the strings really slack?

[DrZEEworkshop]

@DoctorRazzArea4

strings are d'addario EXL120: .009 .011 .016 .024 .032 .042, it's Texas Special Strat. No speacial tuning or anything...

No clue about where asianish-ness comes from thouh ..heh heh :) Maybe it's because I unintentionally have a habit slightly squeeze my left fingers more at the very same time as I pick the string, so it's like a super-short vibrato at the attack of the note and a bit shortly after the strike. I am not very good at playing "analysis" ... :(

/mike z

[DoctorRazzArea4]

@DrZEEworkshop I'm an avid guitarist and I love it!

[thangamajig]

Thanks for the reply. I was thinking of building one for my fisher 500C.

[DrZEEworkshop]

@thangamajig

In general if you are going to build exactly the same circuit as Fisher K-10, then:

first you need to know the input impedance of the reverb tank you are going to use.

Second , "view" your situation as it's 12AU7 single ended amplifier (that's what the second section of 7247 tube is in the rev. driver amp).

You can try then contacting support at hammondmfg d o t com and see what they have available for your situation.

btw, for 500C you gotta have the original K-10 :)

[thangamajig]

Can you recommend a matching transformer to replace T2 in the Spacexpander reverb unit.

[DrZEEworkshop]

@thangamajig

I have no idea, as I had no reason to "ivestigate" what exactly the original transformer is there.

It is there to match the Tank's input impedance , which is about 1.4kOhms in Fisher Tanks.

So it can 5K/1.4K or 10K/1.4K ..??.I don't really know.

If you are building from scatch, then you could try fender transformer with 5kOhms Primary/8 Ohms secondary and use type 4 accutronics tank with part# starting as 4AB (A=8Ohms input/B=2250 Ohms output).

Just guessing, really :)

[MsBirdylady]

is that amp old 3m revere

[DrZEEworkshop]

@MsBirdylady

Yes , it was T-2200 stereo-companion unit for T-2000 tape recorder converted to a small Guitar amp.

I have detailed page for that project at my website. I can't post link in comments. But, You can go to the project-link in this video description, from there go to Workshop Amplifiers section and from there go to "Blues Traveler" practice/recording amplifier project.

/mike z