SDA

Studer A800 Resurrection…

Author: matthew; Published: Dec 27, 2008; Category: New Studio; Tags: ; No Comments

Way back in ought-six, Steve, the owner of Echo Mountain, acquired three Studer A800 machines in dubious condition. One was rebuilt and has been in use as Echo’s 2″ 8/16/24 track for the last two years. The remaining two have languished in the amp room as parts machines, keeping the primary 24-track working more or less flawlessly. They came in on a truck from NYC and all had been mostly stripped of tantalum/poly caps due to someone deciding that capacitor technology was old and bad and would catch fire. While it’s true that tantalum caps love to fail short I think the solution applied of replacing them all with electrolytics was ill-chosen as a long-term remedy, but great for job security for whoever gets to re-cap the machine every five or ten years. It’s true, we decided to stick with electrolytics as the more durable technologies are crazy expensive. So, I give you the re-cap team:

This project took place during two four-day sessions over the last two months and was overseen by Greg McNeer and myself. Prior to working on the tape machine itself I robbed the power supplies from both for rebuilding. Each A800 has five separate power supplies in a sweet daisy chain. The audio supplies have a fancy interlock while the transport/logic/etc. supplies are more straightforward.

Problem – Like most 80′s technology the wires carrying power and the .1″ molex used to connect it aren’t really rated for the current demanded (and heat created) by the machine, so the wires are brittle and corroded and the connectors are stiff and burnt.

Solution – Replacing worn-out wire and parts. I selected some 16 ga. wire with a higher-temp insulator than the original and kept wire colors the same so the excellent manual could still correspond to the real circuit. I didn’t have a better connector option that I could stuff in the holes available so i stuck with sweet sweet molex.

Problem – The middle audio supply negative rail is getting pulled down.

Solution – An electrolytic in the back plane of the middle card cage has failed short. With it replaced all power supplies are operating to spec.

The heads have been sent for re-lapping and capstan and tach rollers sent for sandblasting. The tape path is square according to the alignment blocks.

New mains for a new room

Author: matthew; Published: Nov 17, 2008; Category: New Studio; Tags: , , ; No Comments

looking in the door of the new control room.

looking in the door of the new control room.

a hole for the connector.

a hole for the connector.

Today was a day of new mains for the new control room. I connector-ized the 10-gauge speaker cables I pulled through the studio conduit with the Amphenol connectors I got from PEI genesis. I poked holes in the speakers for the panel-mount connectors and got a brand-new 140-watt soldering iron that would handle heating such large wires and solder cups. New tools are so exciting. I don’t normally deal with wires this substantial and had to build a little jig to get them all in the same plane as the solder cups/pins without significant bends.

male connector

male panel-mount.

female.

female from the amp.

The holes for mounting the panel-mounted male connectors are super small: you can see the #4 brass wood screws used to mount it in the photo at the left. I was worried the little screws wouldn’t be beefy enough to actually hold the connector, but once it was all assembled and mounted this solution seemed sufficient. (I have some 4-40 screws/lock washers/nuts just in case.) Luckily, this assembly will just sit there 99% of the time without much disconnecting/reconnecting. I do wish the mounting screws were black anodized, but since this whole thing will sit inside the wall I guess it’s no big deal.