VINTAGE MADE IN THE USA 1962 EICO ST-70 STEREO TUBE AMP "MODDED" FREE SHIPPING

This was a storage locker find it had been stored well over 20 years and was in pretty bad shape when I got it but I've brought it back to life it's still not 100 percent perfect but it's in functioning condition, please read the entire description and there is a demo video after the last picture make sure to check that out so you can hear it works.    

A little about the Eico model ST-70 it's a complete high fidelity stereophonic control center and a pair of 35 watts amplifiers, all in one chassis.

With it, you can select, preamplifiy, and control any stereophonic or monophonic source and feed it through the self contained dual 35 watt amplifiers to a stereo pair of speakers.

PRODUCTION 1962-63

ORIG. MSRP $99

FACTORY SPECS:

Power output: 35 watts per channel into 8Ω (stereo)

Frequency response 18Hz to 43kHz

Total harmonic distortion 1%

Damping factor 6

Input sensitivity: 4mV (MM), 480mV (line)

Speaker load impedance: 4Ω to 16Ω

Valve complement: 3 x 12AX7, 2 x 12DW7, 2 x 6SN7GTB, 4 x 7591, 1 x GZ34

Dimensions: 5-1/8 x 15-7/8 x 15 inches

Weight: 40lbs

STOCK NO. 6607066038440

As stated above this was in poor shape when it came to me it was very dirty the power cord was damaged the volume pot was bad there's several bad switches I did however go ahead and clean all the pots and switches and I had to put the correct 3 amp fuse in it someone had put in a 15 amp fuse at some point.

There were no feet on the bottom plate so I installed some nice modern black and gold plastic feet.

All the tubes were removed and the sockets checked for cracks plus the sockets have all been sprayed with Deoxit as well as the tube pins themselves then the tubes were wiped down and reinstalled the sockets are all nice and tight 

Installed Tube List

4-Original 7591 made by Westinghouse for Eico

1-GZ34 Made in Great Britain Rectifier Tube

2-6SN7GTB Made by General Electric for Eico

2-12DW7 Mullard made in Great Britain

2-12AX7 RCA

1-12AX7

These amps are a popular modding platform there is a lot of info on these online see the Tronola mod page:      

Mods I’ve Performed  

1.The 4Ω tap is grounded from the factory so I have removed it all together this is a well documented mod

2. There was a center channel output from the factory and was unneeded so I have removed it this is a well documented mod

3. You used to have to use a jumper wire on the speaker outputs in order to make the speakers work it was just dumb so I rewired the speaker terminals to be “normal” and replaced the screws with thumb knobs again this is a well documented mod       

4. The loudness circuit from the factory did not function correctly some people mod the circuit but I have removed the loudness circuit all together as the factory volume pot was bad it contains taps for loudness circuit I did not have the correct volume pot for this with the taps which runs $100 if you want to put the loudness circuit back in 

5. There is a weird balance check circuit which I removed this is a well documented mod

6. There is a weird speaker phase circuit which was removed another well documented mod

7. The on off switch was on the front shaft of the treble knob from the factory again weird this is another well documented mod where the power switch is moved from the pot to a dedicated on off switch in this case I used the old switch left over from removing the speaker phase circuit and moved the power wires to it to become the new off on switch   

8. I replaced the original power cord with a new cord

9. I removed both the hi pass and low pass filter circuits

10. the tone stack was bypassed completely   

11. The cage from the factory was a yucky beige color so I painted it flat black

12. The factory knobs were a ugly cream color so I painted them flat black  

13. I painted the switches flat black to match the new color scheme

14. I removed the brown paint from the strip across the front where the switches are to revel the gold anodizing underneath

The only switches that are still in circuit are the tape EQ and the tape mon and the old speaker phase switch is now the on off switch and it now just basically a straight power amp  

I'm seeing these listed on Flea Bay in working condition into the $800 range plus shipping non-functioning parts units are in the $250 to $500+ plus shipping

Comes with owners manual service manual and mod sheet