History
The Studer A800 was the replacement for the industry standard A80 model, that was found in many high end studios from starting in 1982. The A800 was heralded as the first microprocessor controlled multitrack deck, and came out in 1978. A good summary of the deck is here:
https://www.vintagedigital.com.au/studer-a800/
I got a call around 2021 from Robert Darch, whom I’d also purchased the Mushroom Studios Studer A80 from (see the rebuilding article on this website of the A80) https://reeltoreeltech.com/the-rebuilding-of-the-studer-a80-mkii-24-track-from-mushroom-studios-the-bongo-deck asking if I wanted to buy the A800 that came out of Little Mountain, which countless hard rock and heavy metal bands recorded on in the 1980s and early 1990s. Of course, I couldn’t turn it down. By the time I got the deck, it was in rough shape. It had been used as a spare parts unit to keep the two other A800s at Little Mountain going, and while the deck was complete, every one of the 6 power supply modules was defective, having come from the two decks still in service.
As with all good ideas, the deck ended up sitting idle for three years in the corner of the shop.
Sidestep to 2023, and I had purchased another Studer A80 MKIV out of the Home Studio out of Nashville, Tn. It arrived at the shop, completely shrink wrapped. It looked OK, so I signed for it, and the truck driver drove away. The one thing to know about trucking companies, is that as soon as you sign the waybill, you sign for it ‘received in good order’, and filing an insurance claim becomes very difficult since it was signed for without making note of any damage. Well, this time I shot myself in the foot by not inspecting the deck properly. As I unwrapped it, I could see that apparently another heavy pallet was stacked directly on top of the deck, as no two sides were square, and both the transport and electronics chassis were badly torqued. Even the takeup reel left on the deck was badly bent.
I posted in the Studer Facebook group, asking if anyone was selling a Studer A80 chassis, and that I didn’t need the transport or any electronics. I just required the frame to transplant my deck in to. Someone responded, saying that they came up on eBay or Reverb every year or so, and to keep an eye out. I did just that for about 3 months, and the A80 turned into another deck shoved into the corner of the shop.
Fast forward to March of 2025, and I was listing an item for sale on Reverb, when along the feed at the bottom of the screen came a Studer A80 24 track chassis and frame. It was complete with transport, but no audio electronics were included – for the paltry price of $800 US. Now THIS is what I needed to complete the A80 that had been sitting in the shop for 2+ years. I emailed the seller, asking if the heads were included, as the ad didn’t state one way or the other. And, to my surprise, the next morning I get a call from the seller who turned out to be the owner of Ardent Studios in Nashville:
Starting from humble beginnings in 1966, it now is a 22,000 square foot studio. Check out the client list on the website above, it’s insane.
After chatting a bit about the Studer A80, and the history of Ardent, I asked the question that I should know better than to ever ask ‘Do you have any other reel to reel gear that you want to get rid of?’ Well, the next morning, I went to the bank to get a significant bank draft, to purchase:
- Studer A80 frame
- 2 Studer A800 MKIII
- 1 Ampex ATR 102 ½” 2 track deck
- a large pallet full of parts for the above decks
Naturally, I justified the purchase so that I could have a working A800 deck while I worked on the Little Mountain one.
The equipment came in well packed, as I’d sent crates down to Ardent from Uline. I unpacked it.. and then the decks sat for almost another year until Christmas of 2025, when I decided to get to work on one of the Ardent decks, and then to continue onto the Little Mountain one.
The older Studer A80 24 channel decks use 430 capacitors, which all need to be changed out to make the deck reliable. The more complex Studer A800s were about 1200 each. Needless to say, the price of capacitors increased significantly between 2024 and 2026, and in January of 2026 I put an order in with Mouser (electronics supplier) in excess of $2,500 CDN. This included 2400 caps, which was enough to recap 2 of the three decks in stock. That didn’t include the larger capacitors in the 6 power supplies, which were substantially more money. Another order went into Mouser for another $600 to recap 2 deck’s power supplies.
The Rebuilding Begins
Since I’d never worked on a Studer A800, I decided to start with one of the Ardent Studio units, as I was assured that the decks needed servicing, but were complete and running when last used. I figured one complete, working deck would be a good starting point in case I needed to test boards or power supplies from the Little Mountain deck, to swap into a working unit so as to confirm proper operation (or not).
I started with the transport section of one of the Ardent decks in February 2026, and since I wanted to check the transport first, I didn’t bother unpacking the VU meter electronics section, as the transport should work independently of the audio section.
To my pleasant surprise, the first deck only had 5300 hours on it,which is relatively low all things considered. Things got delayed due to me not being able to find the power cords for the decks in the Ardent purchase, so I picked up three of them on eBay. When they came in, I cut off the 20 amp plug, and put a heavy duty 15 amp on it. The decks can run on a single 15 amp, 120 volt outlet, but you better have all 15 amps available from the circuit breaker! (Many studios will split the power from the transport and audio cards, and run each section off a separate outlet).
I powered up the transport. The LEDs lit up, the counter came on, and FF and REW worked fine. The reel tensions and overall actions of the transport seemed to be within calibration. Then I hit Play. Nothing. No lights, no signs of life, nada. While the service manual is 2” thick, it assumes that the deck is completely set up, and doesn’t account for user errors.
Thus began 10 hours of labor, troubleshooting the ‘play’ section. I’ll be the first to admit, I am not super fluent with digital microprocessor circuitry, I am an analog guy. While the play button switch is analog, it is changed to a digital 8 bit data line within the deck, and ultimately the digital play command is changed back to analog signals, triggering the brake release, the pinch roller engagement, and the Play button light.
Much of the 10 hours was spent tracing the data lines between the various cards, and they all checked out fine. I swapped over all of the transport cards, as a good set of spares came with the Ardent purchase, and I also swapped over the cards from the Little Mountain deck. Nothing would get the play button to work. As I shut down the shop at 9 PM on a Friday night, I glanced over at the Little Mountain deck that was complete, with the VU meter section installed on top of the transport. I realized that above the 24 VU meters was a narrow single space unit that had some transport control buttons on it. Could it be that the single rack space unit needed to be connected to the transport in order for the play button to work? I was determined to check that first thing the next day.
So, Saturday morning at 7 AM, I pulled the control unit from the Little Mountain deck, connected it to the Ardent deck, and pressed play. I got.. NOTHING. I then also saw that none of the LEDs above the buttons on that control panel lit up when the corresponding button was pushed. Going back to the service manual, I traced the LED power supply to one of the audio power supplies that I hadn’t plugged in, as I wasn’t working on the audio section. I plugged it in, hit play.. and the deck sprang into play mode!
Lesson learned after spending 10 wasted hours on troubleshooting something that was user error: Plug the entire deck in before assuming there’s a fault in the deck. On the bright side though.. I know the play button command, from button to pinch roller, inside and out as a result of said troubleshooting.
After letting the transport play through a roll of tape, and playing with some of the functions to see what the deck could do, I determined that the transport was working well enough to move onto the audio section. With the help of a friend, we lifted the meter bridge onto the transport, and connected all of the multipin connectors.
I decided to roll the MRL calibration tape I had, to see how far off the deck was from indicating accurate levels on the VU meters. This deck has two XLR sets of outputs, which results in twice the calibration needed. Skimming through the calibration procedure, I let the MRL tape roll at the 1Khz test tone, and found that the levels were off by a few db across the board.
It took about 3 hours to get acquainted with the playback of the deck, but once I got on a roll, I managed to dial in all 24 channels of both outputs to +3db:
Recapping
Mid-February I spent $2,500 CDN from Mouser Electronics, ordering all brand new name brand capacitors to recap the entire audio section of two of the A800 decks. It was the largest order of capacitors I’d ever placed, and the heap ended up being smaller than expected:
There’s nothing particularly daunting about recapping a large deck like this, in fact I find it a bit cathartic. Throw on some music, use a good soldering iron and solder sucker (Metcal iron, and Hakko desoldering tool), and the time flies by.
After I’d recapped the first Ardent deck, I decided to also do the Little Mountain deck. It had already been recapped by the world class tech, John Vrtacic back in 1998, according to his stickers on the power supplies. However, considering the time and hours elapsed since he recapped them, I did it again.
I ran across some bizarre problems while testing the Little Mountain power supplies. Each power supply that drives 8 of the audio channels houses two 15 volt power supplies, plus one 6 volt supply. While two of the power supply boxes worked fine, one did not. One 15 volt supply was stuck at 23 volts, the other one at 0.4 volts. These supplies are fairly simple yet robust designs. After doing some digging, I found that a previous tech (post John Vrtacic!) had installed a NPN transistor instead of a PNP one. Installing a correct transistor cured the supply that was sitting at 23 volts, and brought it right down to 15 volts.
The supply that was dead was a bit more simple to figure out. The last tech had switched the input and output wires to the voltage regulator.
The problematic power supply had suffered from significant heat damage to the regulator PC boards as well as the wiring, to the point where the insulation got brittle, and had split in several places. I decided to replace it with a good used power supply found on eBay.
More Little Mountain Sound memorabilia!
Stay tuned for part 2, once the units have been completely recapped, and the calibration and adjustment procedure starts!!