welcome to our dealer in Massachusetts - Bob Latino
Bob not only sells and supports our VTA70 PCB, he also sells BRAND NEW Dynaco ST70 kits and ready-built amplifiers!
 
VTA70 amp VTA120 amp
1. The new STAINLESS STEEL chassis is identical in size, shape and markings to the older original nickel plated steel frame.
This upgraded chassis is NON-MAGNETIC and removes any magnetic interference effects of a steel chassis on the audio circuitry.
2. The new USA made power transformer has a higher stack lamination than the original Dynaco power transformer and is rated
for 120 volts instead of 115 like the old design. The two tube heater legs are rated for 5 amps each instead of 3 amps each
like the old design. This beefed up transformer (which has a bottom plate like the original PA-060 to prevent EMI from
the transformer from reaching the audio circuitry) allows the use of KT88 output tubes in place of the EL34 tubes for
a slightly different tonal presentation. Four heavy duty neoprene isolation mounts are used to attach the transformer to the chassis.
3. The A-470 output transformers are brand new USA made custom production transformers. They use the same interleaved/layer winding
technique as the original cloth lead A-470's and incorporate the same high quality M-6 grain oriented laminations.
They are dimensionally accurate to the original design and have a durable heat resistant black epoxy finish.
4. The old stock 30, 20, 20, 20 electrolytic quad cap which had marginal storage capacity for this amp has been replaced by
a 80, 40, 30, 20 quad cap for almost double the power storage capacity.
5. The upgraded VTA driver board uses three new 12AT7 triodes in place of the two mediocre sounding 7199 pentode/triode tubes.
Dynaco saved money using a two tube 7199 board design but made some serious compromises in sound quality.
The older ST-70 design had one bias control for each channel whereas the VTA board has a separate bias control for each of
the four output tubes. This design allows for individual adjustment of each output tube bias.
Matched pairs or quads of output tubes are not necessary with this design.
Eight quality Sprague 716P "orange drop" coupling caps are included with the board.
6. The input jacks are gold plated and have a wider spacing to allow for newer design thicker interconnects.
7. The output jacks are modern gold plated 5 way binding posts.
8. The 7 octal tube sockets are modern high quality Celanex sockets with cadmium plated pins.
These sockets are very durable and more reliable than the older stock phenolic tube sockets found in the original amps.
9. Includes two triode/pentode switches to allow switching between these two modes of operation.
The switching may be done while the amp is running to compare the two sonic presentations.
brand NEW ST70 amplifiers, in KIT or ready to go!
"Shipping costs will be invoiced separately after your purchase of an amp kit - 36 pounds for the ST-70 and 45 pounds for the ST-120.
Kits to the USA shipped by UPS Ground or USPS Priority Mail. Shipments to Canada by USPS Priority Mail International ONLY.
Shipments to areas other than the USA and Canada will be shipped with a tracking number by USPS Express Mail International ONLY.
"
$639 + shipping IN KIT FORM with all parts but NO TUBES
$739 + shipping IN KIT FORM with all parts and tubes and EL34 output tubes
$799 + shipping IN KIT FORM with all parts and tubes and KT88 output tubes
$845 + shipping WIRED with NO TUBES
$945 + shipping WIRED with ALL tubes & EL34 output tubes
$1005 + shipping WIRED with ALL tubes & KT88 output tubes
240 volt operation add $35 to KIT amp price
add capacitor upgrade for $45 (4 Power supply and 4 hand matched Russian K40-Y PIO coupling caps)
new item
A new OPTION for your ST-70/ST-120 kit is a stepped/attenuator to replace the unused stereo/mono switch on the front of the amp. (see photo)
With this attenuator you can now use your ST-70 or ST-120 amp WITHOUT A PREAMP. Just plug your high level input source (CD player, FM tuner etc.)
directly into the input jacks of your ST-70/ST-120 and control the volume of your music system with the stepped attenuator.
The attenuator may also be added to any Dynaco ST-70. You can also use the attenuator WITH a preamp as a master level control.
This is a nice feature if your present preamp has the volume come on too quickly in the first quarter turn of the volume control.
Comes with black aluminum knob and complete instructions for installation.
+$50 (if purchased with one of the kits on this page)
- - - - - - - - - - - - - - - - -
+$55 (if purchased separately to add to your present ST-70 amp)
click here for NEW item -- ST-70 rebuild kit!
Triode/pentode switching kit
No need to order the triode/pentode kit if you are ordering any ST-70 or ST-120 kits listed on this page, as it is included with all these kits.
This kit may be added to any amp driven with the VTA mod PCB to allow your amp to operate in either the normal pentode ultralinear mode or at the flick of the switch
in the sweet sounding triode mode. Simply remove the old bias pots and install the switches in the empty 3/8" holes.
Note - Kit cannot be installed in a stock amp which still uses the old original bias controls. Comes with all parts and instructions.
$39 with FREE First Class mail delivery in the USA.
here's a photo of the ST70 amp kit assembled by Bob
here's a great photo of the internal wiring on Bob's VTA70 amps, with the Triode/Pentode switches . . .
you can send email to Bob Latino
directly here for info on these complete kits or amps . . .
new VTA120 amp !!
Now available for those that need a little more power is the Dynaco VTA ST-120.
The VTA ST-120 is a 60 WATT PER CHANNEL amplifier built on the same ST-70 stainless steel chassis as the amp pictured above.
The VTA ST-120 uses three custom wound USA made transformers and is available as a KIT amp or completely WIRED and tested.
This amp has the same quality components as the VTA ST-70 listed above. The optional tube set has a GZ34 rectifier,
three 12AT7 driver tubes and a matched quad of KT88 tubes.
The power transformer instead of 360-0-360 secondaries like the ST-70 has 420-0-420 secondaries and puts about 485 volts on the plates
(pin 3) of the output tubes. The ST-70 puts about 420 volts on the plates. The stack lamination on this transformers is about 2.70 inches tall
- my ST-70's power transformer stack is about 2.05 inches high. This transformer weighs about 4 pounds more than the ST-70 transformer
and is rated at 425 milliamps of current flow.
The output transformers have 4200 ohm primaries, 40% ultralinear screen taps and are 3 7/8" tall, 3 1/4" wide and 3 1/8" deep
(about 1/2" taller, 3/8" wider and 1/4" deeper than a stock A-470 output transformer). Each output transformer weighs about
2 pounds more than a stock A-470 output transformer.
The power storage caps have a higher capacity and voltage rating than the VTA ST-70.
"Shipping costs will be invoiced separately - 45 pounds from zip code 01566 by UPS ground"
VTA ST-120 KIT with NO TUBES > $819 + shipping
VTA ST-120 KIT with all tubes > $980 + shipping
VTA ST-120 WIRED and TESTED amp with NO tubes > $1145 + shipping
VTA ST-120 WIRED and TESTED amp with all tubes > $1295 + shipping
add capacitor upgrade for $45 (4 Power supply and 4 hand matched Russian K40-Y PIO coupling caps)
HEAVY DUTY 16g CHASSIS TEMPORARILY OUT OF STOCK UNTIL EARLY AUGUST
Substitute a heavier 16 gauge stainless steel chassis in place of the standard 18 gauge chassis add $15
For more information or to purchase a KIT or WIRED VTA ST-120 - - - Email me at Bob01605@aol.com
Customer Reviews posted on the Internet . . . . . .
here is a review of Bob's VTA ST70 kit on the Audio Asylum
click here to follow link
here is another review of Bob's VTA ST70 kit on the Audio Asylum
click here to follow link
here is a review of Bob's VTA ST120 kit on the Audio Asylum
click here to follow link
here is another review of Bob's VTA ST120 amp on the Audio Asylum
click here to follow link
"What's it like to build Bob's VTA Dynaco ST-70? - Check the link below ..."
step-by-step photos
here's a link to a partial view of the build manual
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tubes 4 hifi |
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"the path of least resistance is through a vacuum"
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