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 tubes 4 hifi
 "the path of least resistance is through a vacuum"

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Tubes 4 HiFi is also known as Vacuum Tube Audio

Our best known product is the VTA ST70 PCB modification for the Dynaco ST-70 amplifier,
that first appeared in a Glass Audio magazine article in 1989.

You can purchase any of our products here from these web pages, making payment with a credit card through PayPal,
or sending us a money order. Thanks for your support!

Please contact me at anytime to order these items or to inquire about other products.

send email to

Due to the Covid-19 pandemic and uncertain shipping times to areas outside the USA and Canada,
I am temporarily suspending all sales and shipments to areas outside the USA and Canada.

our famous VTA70 driver PCB upgrade for your amp!


we've been selling this modification/upgrade for the ST70 for 30 years now!!


Bob's amplifiers

ST70 - VTA70 amplifier

ST120 - VTA120 amplifier

M125 monoblocks

Roy's pages

ST70 mods & upgrades

MK3 monoblocks

custom amps

phono only preamp kits
PH14 PH16

line stage preamp kits
SP10 SP12 SP14

assembled SP14 with remote

premium speaker cables 10'
$49 PAIR + $7 shipping

14g dual cable with gold-plated bananas
compare to Audioquest type 4 at $280 !!

Digital Voltmeter

check your bias !
one for $14 free shipping
two for $22 free shipping

click here to go to our downloadable Dynaco manuals page

our dealer on the east coast is Bob Latino. . . check out his BRAND NEW Dynaco ST70 kits OR ready-built amps
including the high powered stereo ST120 tube amp and new M125 monoblocks click here!!

you can send email to Bob Latino at: for info on these complete kits or amps .


visit our "Dynaco Tube Audio Forum"

our Glass Audio magazine article comparison test of ST70 modifications



send email to ROY at:




 tubes 4 hifi
 "the path of least resistance is through a vacuum"