Repairs Available

If you have a DAP310 for repair or refurbish, please let me know. I’m now accepting repairs. Contact me by email, and I’ll provide you with my contact information. The same caveats apply: Meters, meter bezels, FETs, and several other parts are generally not available. Some DAPs have been butchered beyond repair.

Repair costs are still very reasonable. Most of the (available) parts are in stock. A real concern is that shipping costs are increasing significantly. If you have one you want repaired or restored, don’t wait. I have the time now, but that could change. I also repair and restore Leslie 122, 147, 251, and other model tube-type amplifiers and some tube-type guitar amplifiers.

My direct email address is admin at this domain.

WP Admin


  1. Hey! Thanks for putting all this together. Could I get a copy of the service manual for the 310? Restoring one, it’s got the first 2 cards on the left cancelled out. I believe those would be the expansion circuits?

  2. I am looking for a Dorrough DAP 310 audio processor, preferably in working order.
    Are you aware of any units for sale at reasonable cost?

    • No, not at the moment. If anyone responds to your post, I will forward it to you. “Reasonable” is in the eye of the buyer. How much are you willing to pay for one in good condition?

  3. The DAP310 power supply upgrade calls for an LM342-10.
    Is this still available anywhere, or is there a current substitute for it?

    • The UA7810 should be a direct replacement. I’m installing one later this week. Digikey has them. Look for part number 296-21622-5-ND. It’s just a 10 volt reference. You could use an LM317 configured for a 10 volt output.

  4. I am looking for a replacement DAP310 output meter (Modutec).
    Also I would like to find a replacement back panel for a DAP 310, (the panel
    that attaches behind the audio cards).
    Thank you for any info you can provide.

  5. LM342-10, voltage regulator can be replaced with a LM 7812. All it is doing is creating a reference voltage. You can adjust that voltage by adjusting the trim on the circuit board. I’ve done this on three or four different units and they work perfectly

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