Brand new KIT or WIRED Dynaco ST-70 or ST-120 tube amplifiers - Bob Latino
Also the NEW 125 watt M-125 monoblock KITS - See my main web site link near the bottom of this web page
1. The new 16 gauge STAINLESS STEEL chassis is identical in size, shape and markings to the older original 18 gauge nickel plated steel frame.
This 16 gauge chassis is .055 inches thick, and weighs 1.25 pounds more than the 18 gauge chassis. The heavier chassis better supports the
amp's transformers and the extra 1.25 pounds of metal acts as a better heat sink to help the amp run cooler. 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 The old stock 30, 20, 20, 20 electrolytic quad cap which had marginal storage capacity for this amp has been replaced by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 12AU7 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 (9/16ths of an inch) 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. 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 - 37 pounds from zip code 01566 by UPS ground"
$719 + shipping IN KIT FORM with all parts but NO TUBES
$839 + shipping IN KIT FORM with all parts and tubes and EL34 output tubes
$909 + shipping IN KIT FORM with all parts and tubes and KT88 output tubes
$1035 + shipping WIRED with NO TUBES Shipment within 3 - 4 weeks
$1155 + shipping WIRED with ALL tubes & EL34 output tubes Shipment within 3 - 4 weeks
$1225 + shipping WIRED with ALL tubes & KT88 output tubes Shipment within 3 - 4 weeks
240 volt operation add $35 to KIT amp price
Driver board Low ESR Nichicon power supply upgrade capacitors - 2 X 100 uF and 2 X 47 uF + $15 (must be ordered at the same time as a kit or wired amp or extra shipping charges will apply)
Four matched Russian PIO (paper in oil) main coupling caps + $30 (must be ordered at the same time as a kit or wired amp or extra shipping charges will apply)
Triode/pentode kit as used on the VTA ST-70 pictured above. This kit may be added to any VTA board driven Dynaco ST-70
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.
$29 with FREE First Class mail delivery in the USA.
Photo below of the internal wiring of a VTA ST-70 amp 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 3 X 12AU7 tubes, a matched quad KT88 output tubes and a GZ34 rectifier tube.
The power transformer instead of 360-0-360 secondaries like the ST-70 has 410-0-410 secondaries and puts about 500 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
This transformer weighs about 4 pounds more than the stock PA-060 power transformer as found on the ST-70
and is rated at 450 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. The ST-120 may be used with either a GZ34 tube rectifier or a solid state rectifier.
VTA ST-120 KIT with ALL TUBES > $1099 + shipping
VTA ST-120 KIT with NO TUBES > $909 + shipping
VTA ST-120 WIRED and TESTED amp with ALL TUBES > $1495 + shipping - shipment in 3 to 4 weeks
VTA ST-120 WIRED and TESTED amp with NO TUBES > $1305 + shipping - shipment in 3 to 4 weeks
Optional > Power supply upgrade capacitors > +$15
Optional > Matched set of Russian PIO (paper in oil) main coupling capacitors > +$30
Optional > Stepped attenuator kit into a KIT amp > + $50
Optional > Stepped attenuator into a WIRED ST-70 or ST-120 is + $75
NOTE - This is an ALTERNATE WEB SITE and may have outdated pricing. Please go to my main web site at the following link >
Tubes4hifi VTA amp kits
For photos and more information on the ST-120 amp KIT or the all new VTA M-125 125 watt
monoblock tube amplifier KIT... > Email me at > Bob01605@aol.com
"What's it like to build a VTA Dynaco ST-70? - Check the two links and reviews below ..."
Building the ST-70 kit amp
Building the ST-70 amp kit on Audiokarma
Review #1 on the Audio Asylum
Review #2 on the Audio Asylum
Review #3 on the Audio Asylum
Bob Latino Dynaco Tube amps |