Update My Dynaco Store

Everything you need to update
your Stereo 120 or PAT-4, and now the GT-101 Power Amplifier Kit!

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Free shipping in the lower 48 states for orders of $89.00 or more
(GT-101 not elegible for free shipping)

The GT-101 Stereo Power Amplifier Kit (GT-101K) - $299.00 plus $26.00 shipping (48 states)

GT-101 viewed from above GT-101 viewed from the top with the cover removed GT-101 back view

This is a complete, from the ground up, Stereo Power Amplifier Kit. Just add solder and your assembly skill to make the sweetest sound you'll ever build. For a more complete description visit the Akitika Website which features the GT-101. Like all our kits it comes with a great step-by-step manual. Unlike the updatemydnaco kits, you don't need any old hardware as a basis. Everything that you need to build a great sounding power amp, except the solder, comes in the kit. We will quote shipping options and costs for orders outside the 48 contiguous states.

Volume Control Kit for the GT-101 Amplifier (VC101) - $9.95

volume control kit installed into a GT-101

Note that the volume control shown in the picture above is not included in the standard GT-101 kit.

Most times, the GT-101 is used with a preamplifier. However, a small but growing group are dedicating a GT-101 to a CD player. In many cases, the CD player doesn't have a volume control, so adding the volume control to the GT-101 makes great sense. This kit has a quality stereo volume control, shielded cable, and an attractive knob. Installing the kit requires you to drill a hole in the front panel of your GT-101. Here's the Installation Manual for the volume control kit.

Visit the Akitika Store if you'd like to buy the sub-modules from a GT-101 for your own special projects

Selling separate components from the GT-101 began when a customer wanted to build a seven channel amplifier. He bought 7 amplifier modules, 3 power supply regulators, and 3 power transformers. The light-bulb over my head went on...Maybe lots of other DIY'ers would like to build special amp configurations in their own custom enclosures. By offering the modules and parts, everyone wins.

Do you have a custom amplifier project in mind? This is the place. Have questions? Send email to dan@updatemydynaco.com.

Two Single Channel Amplifier Module Kits (TCK) - $89.00 gets you both channels!

one channel kit of parts parts common to both channels one channel kit of parts

The kit includes circuit boards and parts, enough to build a left and a right channel amplifier module to replace the original amplifier modules in your Stereo 120. We supply everything you need, electronic components, PCBs, thermal compound,solder, new hardware, and new wire (you'll also recycle some wire from your old amp modules).

Two Assembled and Tested Single Channel Amplifier Modules (TCA) - $139.00 gets you both channels!

two assembled kits

You get two assembled and tested updated amplifier modules. You still need to remove the old amplifier modules from your Stereo 120, mount, and wire in the updated modules. We give you all the components and hardware you need to complete the job.

This link lists the Assembly Manuals for the various possible final assembly options. Select one of these manuals to guide you through final assembly, e.g. wiring the assembled modules into your Stereo 120, depending upon whatever other options you may have ordered.

10,000 uF Speaker Cap Upgrade for the TCA or TCK (10KUF) - $9.00 gets you two upgraded channels

comparing a 10,000 uF cap to a 3300 uF cap

The standard TCA or TCK kits listed above come with a perfectly reasonable 3300 uF output capacitor, as shown on the right. That's big enough that the output filter formed between your 8 Ohm speaker and this cap is -3 dB at 6 Hz. That's quite low enough for most folks, but not for all! For another $9.00, you can bump both output caps up to 10,000 uF (the cap on the left), and move that -3 dB point down to 2 Hz. That does get you a little more output power at the lowest frequencies, and a bit lower distortion down there also. Do you need it? Probably not. But do you want it?

At this great price, we can only accept an order for the 10KUF when you order a TCA or a TCK at the same time.

Two Super Heatsinks (SHS) - $20.00 gets you super heat sinks for both channels!

assembled kits with super heat sink option

The picture above shows two super heatsinks. The super heat sinks are 3 times the thickness of the originals. Deliver more power longer, while keeping the amp cooler.

Vinyl/Rubber Feet (FFT) - $4.99 for a set of 4!

a set of four new feet around two old feet

If your Stereo 120 is original, the Vinyl/rubber feet on the bottom are 40+ years old. In that time, they dry out and fall to pieces. We've got replacements that fit perfectly, except they're a bit taller than the original feet. The picture shows two original feet, surrounded by four of the taller feet. The increased height is a benefit, as it allows better air circulation, reducing operating temperature and enhancing component life.

Power Supply Replacement Capacitors (PSRC) - $15.00

new capacitors and old

Electrolytic capacitors don't last forever. The silver capacitors in the background are the originals. The small one on the left was used for C9 (1000 uF at 100 V), and the large one on the right was used for C12 (3300 uF at 100 V).

The two black capacitors in the front are 3900 uF 100 Volt capacitors. They fit nicely into the existing clamps for C9 and C11. The new caps are meant to be used with an update kit. The upgraded amplifier modules don't need C11, so we replace the original C11 with 3900 uf, and then use it to supply the C12 function with upgraded amplifier modules. Of course, you can add a really big C12, as shown below, for even more energy storage.

If you want to replace all the big power supply capacitors and you have original amplifier modules then you'll need to also pick one of the C12 options shown below.

There are two different sets of directions for using the PSRC with the upgraded amplifier modules...

Replace C12 for Better Bass (C12XX, see table) - $21.00

20,400 uF replaces 3300 uF for better bass

Components in the C12DD kit are pictured above

This table shows the upgrade kit to order, depending upon the modules in your Stereo 120. Each kit has just the right components to maximize the performance of that particular configuration.

Power Supply Amplifier Modules Upgrade Kit Order

The stock value of C12, 3300 uF, really isn't big enough to get the maximum amount of low frequency power out of your Stereo 120. These kits provide a Dynamite Capacitor Configuration of 3 6800 uF 80 Volt caps. You'll wire them in parallel to produce a mighty 20,400 uF. They also include the ancillary components needed to maintain long life and best performance. View the C12 Installation Manual. Read more background on the dynamite capacitor configuration.

Stereo 120 Replacement/Upgraded Power Supply Kit (PSUG)-$39.00

replacement power supply kit

Does your Dynaco Stereo 120 have power supply problems? Our kit may be just what you need. The original Dynaco Stereo 120's power supply was a classic, clever, Dynaco design. Unfortunately, its performance depends upon unpredictable parameters in the transistors. As such, it has a reputation of being a bit temperamental, and a bear to repair.

Our new design drops right in, replacing the PC-15 regulator board and Q9 pass transistor. It re-uses the existing capacitors, power transformer, and heat sink. It has slow start, predictable current limiting, short circuit protection, accurate output voltage, super low output impedance, and low noise. It's compatible with both the original Dynaco Amplifier Modules, and the Updatemydynaco replacement amplifier modules.

The kit contains everything you need to get your power supply into tip top shape...

The picture shows an assembled power supply, but remember...you will receive this as a kit. The kit is easy to build. It uses all through-hole components. The circuit board has been specially designed with generous spacing between all the soldered points, making assembly easy. P.S. - I'm sure that some buyers of this replacement power supply will do so in the search for superior sound, even if their existing power supply works fine.

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Assembled and Tested  Stereo 120 Replacement/Upgraded Power Supply Kit (PSUGA)-$79.00

This is an assembled and tested version of the PSUG kit shown above. You still have to install it into your Stereo 120, but buying in this form may be the right choice for some. We build and test each to order, so shipments happen about 1 week after your order is received.

Blue Light for PAT-4, Stereo 120, Stereo 80, or SCA-80 Power Switch (BLUE)-$7.95

blue light on a dark night

The original power switches have classic orange neon-lamps. Swap them for beautiful blue using our step by step directions... Blue Light Assembly and Installation Manual. Not so many steps in this case, so you should be able to complete a Stereo 120 lamp swap in about 1 hour. This mini-kit gives you eight tiny blue LEDs preassembled onto a PCB about the size of an NE-2 lamp. You install the included dropping resistors and heat shrink tubing to complete assembly, then swap out the orange NE-2 for beautiful blue. You can put blue light anywhere an NE-2 lamp can fit.

Improve Bass with Upgraded Speaker Coupling Caps for Stock Stereo 120 Amplifier Modules (C7X2)-$25.00

C7 Upgrade kit

The original speaker coupling caps were a bit on the small side, at 3300 uF. This kit provides 6 3300 uF capacitors that you arrange in a Dynaco Dynamite Capacitor triple. This yields 9900 uF per channel, producing better bass, more bass power, and lower bass distortion. As always, you get a step-by-step manual that guides you through the upgrade process. You recycle the capacitor clamps, some wire and some screws. We've included special hardware in the kit to make the most cumbersome part of the job go more smoothly. Take a look at the C7 Upgrade Assembly Manual. It's about a 4 Meg download owing to some hi-res pictures that we think will make the upgrade enjoyable.

Order your C7X2 kit today for better, stronger, and cleaner bass from your Stereo 120 with stock (original) Dynaco amplifier modules.

Electronically Regulated Power Supply Kit for PAT-4 Preamp (PAT4PWR) - $39.00

PAT-4 Power Supply

The original PAT-4 power supply was another classic Dynaco compromise, perfectly appropriate for the time. Later, people took the "add a mess o'microfarads approach" to improve it. This new PAT4 replacement power supply beats all those approaches hands down. It is electronically regulated with super quiet 38 Volt and 17.5 Volt rails. The output voltages remain rock steady even as the line voltage wavers and the music plays. I think you'll hear a nice improvement in the sound of the PAT-4 using this power supply.

The picture shows the FR-4 (green) PC board, and the way the replacement power supply elegantly mounts in place of the old capacitor can. The new arrangement dramatically decreases the loop-area of the rectifier input, cutting stray hum fields. The kit comes with everything that you need...PC board, parts, mounting brackets and screws (but no solder).

Here's the Assembly Manual for the PAT-4 Power Supply (Rev A, no longer shipping)

Here's the Assembly Manual for the PAT-4 Power Supply (Rev B, shipping since November 10, 2013).

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Assembled and Tested   Electronically Regulated Power Supply Kit for PAT-4 Preamp (PAT4PWRA) - $79.00

This is an assembled and tested version of the PSUG kit shown above. You still have to install it into your PAT-4, but buying in this form may be the right choice for some. We build and test each to order, so shipments happen about 1 week after your order is received.

Tone Control Switch for PAT-4 Preamp (TCS)-$10.00

switch wire locations

Tone controls can be handy, but sometimes it's great to know what things sound like when they're absolutely out of the circuit. This kit replaces the seldom-used HI FILTER switch with a two position switch. The OFF position turns OFF the tone controls, no matter how they are set, giving flat response. The "15" position restores normal tone control operation. You can easily switch between the two positions. Our careful design makes the switch-over completely free of clicks and pops. So now you can have it both ways...be a purist with absolutely flat response, or use the tone controls when your source material needs a hand.

The kit now includes replacements for the two capacitors most likely to have gone leaky. You'll want to install these caps if your bass control is scratchy. That often will take care of the problem, at least in all those cases where bass control is still in reasonable shape.

Tone Control Switch Assembly Manual

Reduce PAT-4 Distortion by 10X (DRD4)-$5.00

darlington reduces distortion

All the sound in the PAT-4 passes through the high level stage. This kit reduces the distortion in the high level stage by a factor of 10X. You'll replace Q4 in both channels by a specially selected Darlington transistor with a heat sink. Everything that goes through your PAT-4 will be cleaner. The kit includes two new transistors, one for each channel. Distortion Reducer Installation Manual.

PAT-4 Phono Preamp Upgrade Kit (PAT4LP)-$24.00

Phono Preamp Upgrade installed into a PAT-4 Preamp PCB

This kit turns the PAT-4 Phono Preamp into a seriously good piece of gear. It drops the noise by 4 to 8 dB. It makes topology and parts changes that let you get rid of the big electrolytic caps, dramatically improving the sound. It's customizable...you can select optimal gain when you install the upgrade. It lets the PAT-4 handle three phonos. It removes the clunks that always accompanied the switch from high level to low level sources. This is a challenging kit, but you'll love the results. The picture shows the PAT-4 PCB board after the mods of the PAT4LP kit.

PAT-4 Line Stage Replacement Components (P4LSRC)-$30.00

One PAT-4 PCB modified with Line Stage Replacement Components

The picture above shows one PAT-4 PCB modified with Line Stage Replacement Components, and the DRD4 kit (not included)

This kit supplies replacement resistors, electrolytic capacitors, and input transistors (Q3) for the PAT-4 preamp line stage. The kit consists of enough components to do both the left and right channels. The original resistors had 5% and 10% tolerance. The resistors in the kit have 1% tolerance. The original resistors were carbon composition. The new resistors are metal film. Metal film resistors are both quieter and have less distortion.

To minimize your overall work while maximizing your overall performance, you might want to also purchase and install these kits at the same time:

Note that the kit doesn't replace the polyester capacitors as these have an almost indefinite life.

RCA Input Jack Set for Stereo 120 and Stereo 80 (RCAJ)-$4.00

rca input jack replacement

Do your input jacks look oxidized? The ground connection on the Stereo 120 input jacks gets kind of grungy after 40 years. The signal connection probably looks worse, but it's a bit hard to see. All that gunk can cause hum and noise. The RCAJ kit provides new, clean, RCA input jacks for the Stereo 120 or the Stereo 80. They drop right into the existing mountings. You can re-use the original hardware if you like, but we supply new Phillips head screws and keps nuts. Keps nuts have permanently attached lock-washers. This makes reassembly much easier as the lockwasher can't fall off while you reassemble the jacks.

SCA80 and/or SCA80-Q Replacement Cap for C9 (SCA80C9)-$14.00

sca80 C9 replacement caps

C9 is the main filter cap in the SCA80(Q) power supply. If your SCA80 is humming more than it used to, then it's very likely that the original C9 has lost a lot of its capacitance. This seems to be a very common problem with SCA80's (and SCA80-Qs). The SCA80C9 kit replaces the original 5000 uF 80 Volt capacitor with three 3300 uF 80 Volt caps in a dynamite capacitor configuration. bumps the power supply capacitance up from 5000 uF to 9900 uF. You'll get lower noise and better bass.

SCA80 and/or SCA80-Q Replacement Cap for C11 (SCA80C11)-$29.00

sca80 C11 replacement caps

C11 was the silver-can 3-section filter capacitor that supplied power to:

If you've replaced C9 and still have hum it's a very sure bet that your C11 is on its last legs. These kinds of caps aren't available anymore, so we're going to go one better. The original kit used 3 caps and two resistors to make the 24 and 17.5 volt supplies. Simple, yes, but we can do a lot better with an update.

The SCA80C11 kit supplies the bulk capacitance required by the amplifier driver sections. To that it adds the finesse and control of two electronic regulators. One makes the 24 volts for the high level preamp stages and the other further filters that already clean power to make 17.5 volts for the phono preamp. The electronic regulation decreases noise, crosstalk, and output impedance of the power supplies. It also steadies the supply voltages no matter what's happening to the line voltage or the load on the power amps. The SCA80C11 kit's circuit board drops right in, replacing the original C11 with something that will truly upgrade your SCA80's sound.

Pair of Blue LEDs for Amplifier Modules (BLUE2) - $1.00

Everyone loves the look of blue light from their stereo equipment. You can add it to your Stereo 120 or GT-101 amplifier module with this least expensive kit of all. It's just two blue LEDs. The directions are just 1 sheet. Make sure to read them so you can put the LEDs in with the correct polarity the first time!

You remove R9 on each amplifier board, and replace it with this LED. We sell them in pairs so you can do both left and right modules at the same time. On the off chance that this is the only thing you're ordering, then order BLUE2POST, see below, that includes first class mailing in the United States.

Pair of Blue LEDs for Amplifier Modules includes First Class Postage (BLUE2POST) - $5.00

A pair of Blue LEDs. Replace R9 in two amplifier channels. Add more beautiful blue to your updated Stereo 120 or GT-101 amplifier modules This item includes first class postage in the United States.

If this is the only item in your order, it's the least expensive way to go.

Blue LED replaces R9 in a GT-101

Picture shows a GT-101 amp module (not included) with one of the two Blue LEDs supplied installed in place of R9

Stereo 400 Replacement Speaker Relay Kit (RY301)-$24.00

Replacement speaker Relay kit for Stereo 400

You can now get a replacement speaker relay kit for the Stereo 400. It uses a pair of sealed relays with contacts rated at 16 Amps. This exceeds the original relay's current carrying capacity. We've named this the RY301 kit after its designation in Stereo 400 schematics. Here's the Stereo 400 Relay Kit Manual. Note that this is a special order item at present, and has a two week delivery lead time.

Stereo 80 Binding Posts (ST80BP)-$10.00

Stereo 80 Binding Posts outside view Stereo 80 Binding Posts inside view

The Stereo 80 has screw terminals for speaker connections. They're a bit hard to deal with. Here's a neat kit with two pairs of 5-way binding posts and lugs. They fit beautifully, although there is a gap in the center...but that gap gives you room to tighten both black binding posts. No manual available on this one yet...I figure it should be pretty apparent from the pictures above. Just $10.00 gets you easy on/off speaker connections on your Stereo 80.

We Ship to the United States and International Destinations

United States Shipping

In the lower 48 states, we typically use USPS priority mail or first class mail for small packages. Larger packages, like the GT-101, are shipped using UPS ground.

International Shipping

Small packages, under 4 pounds in total weight, ship by First Class International Mail. Larger packages go by Priority Mail International, which takes 6-10 business days. Extra charges are typically involved in international shipments. Our international customers are responsible for paying any applicable duties on their shipments. Here's a link that you can use to estimate the additional country specific charges that you might have to pay.

Attention International Customers!

The Customs Forms require your phone number! Please send your phone number in an email to dan@updatemydynaco.com along with your order. We will contact you and work out the additional charges that may be required for international shipping.

International Shipping Deltas

International Shipping Delta

There are so many options for international shipping that we handle it on a case by case basis. If you're an international customer, we'll calculate if there is a required delta in shipping cost above domestic (United States) rates. You can pay that delta by selecting the correct value from the above International Shipping Delta pull-down menu, then click the the "add-to-cart" button. If you prefer, we can also invoice you separately for the delta in cost for international shipping.

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