Triode Electronics ST70 Dynaco ST-70 DIY Tube Amp Kit !

All parts needed for a complete Brand New TriodeElectronics Upgraded Dynaco(tm) ST-70 Build. PA-060-S Power Transformer, A470-S Output Transformers, C354 Choke, ST-70 upgrade Chassis, ST-70 Driver Board (Our New EF86 Model that now can run 6922 types), Our New, Improved, Capacitor Upgrade board, 77-MIP-8 Amphenol Sockets, AGC Fuse Holder, Power Switch, Gold Plate Binding Posts, Gold teflon insulated RCA jacks, Bias Test Point Jacks, 10k bias potentiometers, offboard resistors included 10ohm biaset resistors, 20ft of brown cloth wire and more! You can also order with our PA-521-S 240v export power version Dual Voltage ST70 Dynaco ST-70 Tube Amp Kit 120/240V ,or without a driver board for -$65 less or with full tube compliment +$100. Drop us a line and we will adjust invoice. Brand New Production. Transformers Made right here in in Chicago,USA,  By a factory thats been making then since the 1950's. We are factory direct dealers and pass the savings on to you. Wholesale prices, at single piece quantities...

The venerable ST-70 (35 watts per channel, 17.5 wpc in class A) was one of the best selling amps of all time for a reason, It sounds great. The original amp was built to meet a price point, so it had room for improvement. This amp has all our most requested upgrades and suggestions. We have been selling these parts and refurbing dynacos for almost 2 decades. Our TriodeElectronics ST-70 with these upgrades will easily outperform most amps costing twice as much as our offering, and comparable to amps costing even more. Detailed pictoral manual for an easy build, and everything you need except tubes ( check out our store for tubes ) !!

Our Kit's are a great choice if you really want to learn more about how your amplifier operates. You see, unlike many other Kit's, you are not totally locked in to only certain components, nor are you stuck with unchangeable circuit values which limit the versatility of your amplifier and further modifications. There's no "big secrets", you don't need permission from a "guru" to change or tweak it, the manual has instructions for about every change you could imagine making. Instructions are included for triode connecting the output tubes, which will give you a taste of hi-end triode-itis for the cost of 4 resistors, about $1. So, you've got a choice..you can just plug in & play, or you can do your own experimenting if you'd like to, learn a lot, and become your own neighborhood Dynaco guru. And you won't break the bank doing it, either. The stock board and parts kit includes, transformers, choke, rca jack, terminal strip, metal film resistors, polypropylene capacitors, wire, bias potentiometer, and sockets. which do just fine..but if you like you can modify many component values and try different or exotic parts and tweak to your heart's content. The boards will adapt to output tubes which need very low drive circuit impedance/ DC grid resistance like 8417's- or may be modified to whip out enough voltage to drive 300B's or 6B4's!! The board sounds fine even with the off the shelf, current production tubes, and special grading and matching is not absolutely necessary. It is a good example of what can be done with the original type of circuit with improved components, and makes a good case for the virtues of simplicity and short signal path in audio design. The TriodeElectronics Mk3 boards emulate the simple but highly effective (due to the short signal path and single gain stage) original Dynaco circuit, but with lower hum, noise, distortion, and a wider voltage swing across heavier loads, than a 7199,6GH8,6BL8/ECF80, 6U8/ECF82 or 6AN8 are capable of. Comes without tubes, see our store for them. The board manual includes information on adapting the amplifier to different output & board tubes, adjusting resistor & capacitor values if desired, plus a comprehensive Troubleshooting Guide.

Chassis:

Stainless Steel, Heavy Duty, Punched, Chassis. Same dimensions as original. Upgrade chasiss has cut-outs in front for modern RCA jacks. These are spaced further apart to accomadate modern cables and jacks. Cut-outs in Back for Binding Posts instead of the original terminal strips. These provide much better contact for the speaker wires, and allow use of banana plugs for quick connections. No need for those goofy octal sockets in the front, so we put the bias points on the top next to the bias pots. Our Latest version of the chassis also has a IEC cut out for the power cord and a cut out for a more heavy duty power switch. Original or repro st70 cages will fit as on original. Nice stainless steel finish. Comes with top and bottom pieces. Custom built chassis made right here in Chicago Il. USA.

Transformers:

PA 060 S Power Transformer: Improved replacement power transformer for Dynaco ST70. Heavier construction, runs cooler, gives better regulation, won't buzz & hum like some originals do. Telfon insulated (instead of cheaper PVC) leads. Built to Last...Our custom made transformers are made here in sweet home Chicago Il. USA as well, by a company with many decades of experience.

A-470 S Ouput Transformers: The primary is wound the same as the original A470, same number of turns, sections and wire size, using the same patented Dynaco winding method, and made on the same core size and material. Only improved insulation material used (thus making the transformer more resistant to abuse). We have sold hundres of these transformers to satisified customers all over the world. This transformer has what you'd expect out of a Dynaco transformer, like healthy low frequency inductance, high resistance to distortion caused by output tube imbalance, and low distortion overall. They're great for both hifi and guitar amplifier DIY projects (such as the Eiclone project at www.diytube.com ) as well as replacements for Dynacos.

This type of transformer can be used with many tube types, such as 6550, KT88, KT90, 6CA7/EL34, 300B, 2A3, 6B4 or push-pull parallel 6BQ5/EL84 & 6V6-GT. It may be used with triode, pentode, or ultralinear (screen tap connection) wired tube arrangements. 4, 8, and 16 ohm taps.

C-354 Choke: 55 ohms, 1.5 henries, 10% tolerance, 2500 volt DC hipot tested, 200 ma DC.

Boards:

EF86 Driver Board:  What's so special about our Dynaco upgrade boards? The object of our upgrade boards is to provide a replacement for the original boards that would result in a perceptible improvement in sound quality and overall performance. These boards emulate the simple but highly effective (due to the short signal path and single gain stage) original Dynaco circuit, but with lower hum, noise, distortion and a wider voltage swing across heavier loads than a 7199, 6GH8, 6BL8/ECF80, 6U8/ECF82, or 6AN8, are capable of. The manual includes information on adapting the amplifier to different output & board tubes, adjusting resistor & capacitor values if desired, plus a comprehensive Troubleshooting and Modification Guide. Board uses two EF86 for and one of either 12AU7/ECC82 (or equivalent), or 12BH7 or ECC99. Our newest version of the EF86 board has been slightly revised to accept 6922, 6DJ8, 7308, and 6CG7 in the phase inverter position as well as 12AU7, 12BH7, and ECC99 that were previously supported.

NEWLY DESIGNED! Upgrade Cap Board: New Updated Version!!! This is a new, updated, version of the classic, SDS Labs, ST-70 Capacitor board. We have upped the capacitance to over 500uF @ 500V (Increases capacitance from original 30-20-20-20 to 40-195-135-135) while at the same time shrinking the board to make it fit into the chassis more comfortably. The board still replaces all bias supply components and we have also added 0.1uF Wima MKP series metallized polypropylene bypass capacitors onto the board. There are no more surface mount resistors as used on the old boards, instead we have standard axial metal film resistors that are easy to mount and solder in place. There is also a cutout on the back of the board to make clearance for using binding posts in the amplifier rather than the original screw terminal strips. The board is a high quality .062 FR4 2oz Copper with plated through holes which allow you to solder/resolder connections with the board already mounted in place. Now with clearer and more detailed instructions. Note left output transformer was mounted askew on this picture. You can line yours up perfectly.

Please check out our other auctions Triode Electronics as we are listing lots of Dynaco upgrades, vintage, +  new tubes, and electronic items. We have what you need for your builds. Check us out. Good Luck.

Export shipping (outside the USA) available only to countries where postal insurance can be obtained for your package.

Approximate shipping weight: 28 lbs from zip 60634. Please see shipping calculator below for shipping cost.

Illinois Residents must pay sales tax. Buyer must respond within 5 days of auction ending. Transactions not completed in 30 days will be resold. Ask any questions before you bid, once you bid you agree to all terms of the auction. Transformers guaranteed 6 months by manufactuer. Please check our other auctions for more tubes, electronics and ham radio goodies. For Tubes and Parts - Check Us Out! TriodeElectronics 5633 W. Irving Park Rd. Chicago, IL 60634 Thanks for Looking... Ph 773-427-8823 (773-Has-Tube) fax 773-327-5652

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