Dynaco Restoration

We offer complete cosmetic and electronic restoration for the The Mark III mono blocks, and electronic restoration for ST70 & MkIV power amps and PAS2 and 3 preamps.


All components, transformers, connectors, and hardware are removed; chassis, transformers, and choke are sanded, primed, and powered coated satin black.  Silkscreen is reprinted in white epoxy ink.  Hardware is replaced with new stainless steel parts.


Power supply rebuilt, using new, high voltage made in Germany can capacitors.  Selenium rectifiers (a fire hazard) are replaced with silicon diodes.

All coupling capacitors are replaced with audiophile grade polypropylene caps of identical value.  We do not use “NOS” (new old stock) caps — The equivalent of asking the hardware store for some “vintage” AA batteries. You know, the kind that have sat in a drawer for a decade….My father tells me beef tasted so much better pre-1950. I believe him. But do I buy New Old Stock hamburger meat?  I think not. “NOS caps” have sat unused for 50 years or more…. And using them is just one bad idea. I recently acquired an unbuilt Eico HF87 kit. Tested all the enclosed NOS Goodall and ‘lytic caps — ALL were bad.

All resistors are replaced with a combination of carbon comps and/or metal film depending on circuit location.

We have done and continue to do thorough side-by-side comparison of numerous brands of caps in order to stay faithful to the beloved vintage tone. We use only recently manufactured parts of the highest quality available, handpicked for their sonic performance. If you believe you have a brand of cap you would like to use, by all means speak up.

Finally, once work is completed, amps are thoroughly bench-tested to make sure they are back on spec. They are then for several days to make sure no kinks arise and to begin the breaking-in process of the new parts, and shipped back to you in some very serious, damage-proof packaging.

I will check your tubes with my three tube testers (including a digital “MaxiMatcher” for current draw matching and will tell you which are good and which are not. But I am not a tube reseller, hence you will need to find yourself a reliable source for tubes. (NOT Ebay!)

All our electronic restoration work comes with a 6-month parts & labor warranty. Shipping costs to and from us are your responsibility.

Contact us for pricing, current turn-around time or any other further information.