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I started on a new project tonight. I found a couple Ampex 350 machines for sale somewhat locally. Took the drive out last night to pick them up. They are both pretty dirty. One is in pretty good shape. The other is a little rough around the edges. I have enough spare parts to fully restore both machines back to their former glory. Both came out of a radio station. I decided I would start on the machine in better condition. Took the electronics apart and set them up on the work bench. Before I power anything on, I always go through it with a fine toothed comb. After opening up the bottom plate, I found about 50 old acorns. Who knows how those got in there. A quick blow with air solved that. These machines had also been modified for use with a Stromberg Carlson 85 watt amp to be controlled from the faceplate of the Ampex. That's the holes you see in the front of the faceplate. I removed the power/ volume control and put that back with the amp. Next up, they moved the line term switch to the front as well. I reversed that and reinstalled it in its normal position. It was a tight squeeze but it went in just fine. While inside, I found a wire that was wrapped around it's terminal, but never soldered. Flowing some solder onto the terminal was oddly satisfying. After testing the power supply cable and AC line for shorts, I plugged it into my light bulb limiter and ran that to my variac. Observing current draw, I slowly brought up the voltage. One of the switches was really dirty and put out a nasty pop to the VU needle which caused it to stick in the "max" position. That's ok, because in fixing that it gave me an excuse to open up the VU meter bulb sockets and clean those out. After a little wipe down, both bulbs work without being intermittent like they were before. The record gain is a little noisy, but I was really surprised it passed decent audio right away. I'll do some tube swapping which will most likely solve the noise issues. The playback gain has the normal Ampex hiss but is otherwise noise free. Cleaning out the pots and switches will help too. The next step is to go through everything with some cleaner. The exposed parts are really dirty. The pots and switches will need the typically conditioning with deoxit and maybe a burnishing brush. Once the electronics are perfect, it'll be time to connect them back to the transport to start on that. Stay tuned!

#vintagerecording #vintagerestoration #ampex #ampex350 #customrecordingco

I started on a new project tonight. I found a couple Ampex 350 machines for sale somewhat locally. Took the drive out last night to pick them up. They are both pretty dirty. One is in pretty good shape. The other is a little rough around the edges. I have enough spare parts to fully restore both machines back to their former glory. Both came out of a radio station. I decided I would start on the machine in better condition. Took the electronics apart and set them up on the work bench. Before I power anything on, I always go through it with a fine toothed comb. After opening up the bottom plate, I found about 50 old acorns. Who knows how those got in there. A quick blow with air solved that. These machines had also been modified for use with a Stromberg Carlson 85 watt amp to be controlled from the faceplate of the Ampex. That's the holes you see in the front of the faceplate. I removed the power/ volume control and put that back with the amp. Next up, they moved the line term switch to the front as well. I reversed that and reinstalled it in its normal position. It was a tight squeeze but it went in just fine. While inside, I found a wire that was wrapped around it's terminal, but never soldered. Flowing some solder onto the terminal was oddly satisfying. After testing the power supply cable and AC line for shorts, I plugged it into my light bulb limiter and ran that to my variac. Observing current draw, I slowly brought up the voltage. One of the switches was really dirty and put out a nasty pop to the VU needle which caused it to stick in the "max" position. That's ok, because in fixing that it gave me an excuse to open up the VU meter bulb sockets and clean those out. After a little wipe down, both bulbs work without being intermittent like they were before. The record gain is a little noisy, but I was really surprised it passed decent audio right away. I'll do some tube swapping which will most likely solve the noise issues. The playback gain has the normal Ampex hiss but is otherwise noise free. Cleaning out the pots and switches will help too. The next step is to go through everything with some cleaner. The exposed parts are really dirty. The pots and switches will need the typically conditioning with deoxit and maybe a burnishing brush. Once the electronics are perfect, it'll be time to connect them back to the transport to start on that. Stay tuned!

#vintagerecording #vintagerestoration #ampex #ampex350 #customrecordingco

Eureka! The RCA 76b console is COMPLETE! Regarding my last post - the grid leak resistors have been replaced, bad tubes in the preamp replaced, some wiring cleaned up in the mixer 5 & 6 push banks cleaned up - all resulting in sweet sweet audio! This console sounds GREAT! There's no other feeling like hearing your mix from this through the control room monitor! This has been a crazy 5 year journey from purchase to completion of the restoration filled with ups and downs. From morons in Michigan to, scammers, hundreds of hours, and facebook strangers who offered their help, when I heard the first playback - it was all worth it! If anyone wants to hear what an RCA 76 is supposed to sound like, shoot me a message! I'd love to send you something that's been recorded on ours. In the pictures, you'll see before and after shots of the guts of the console. It's was really intimidating seeing this for the first time. I had to replace nearly every piece of copper in it. I should have tracked my hours, but it was well into the hundreds I know. In the last pictures, you'll see the console as installed on our "A" control room.

Onwards and upwards. After completing the rewiring, it was on to testing. That moment you always wait for in a repair/ restoration. The first step is to assess the circuit. You start at the first channel, inject a known signal at a known level, and measure that signal at each point along the circuit. Here were my findings: Channel 1 - extremely low level. No reading on the tube check meter Channel 2 - signal stops at potentiometer. Channel 3 - signal is extremely distorted and drops in level intermittently at the output of the program amp Channel 4 - same as Channel 3. Potentiometer is bad? No signal unless pot is open all the way Channel 5 - same as channel 3. Push banks work Channel 6 - same as channel 3. Push banks work Distortion and level issues on the output? Time to break out the scope and probe. The input of the program amp looks good. Following the circuit looks good until you get to T12. After T12, all you see is the sawtooth wave in the picture. Going over the schematic shows that after T12 is a set of resistors off of the output tubes. Grid leak resistors. Using my DMM, I connected one side to ground, and probed the other ends of the resistors. Eureka! Clean signal! Upon testing, 3 out of the 4 resistors are open. This is a wirewound resistor by the way. You can see the cracks in the picture. Now that the console is passing clean audio (temporarily), it's time to test it with some program material. I think the only way to listen to it is to feed is with the Elvis at Sun album! It's just... right listening to those songs on this board. It just sounds right. I can't explain it... So good! Anyways, while I wait for the new resistors to ship, I'll move on to troubleshooting some of the other issues I've found while testing so far. All I've had a chance to look at so far was channel one. The 1620 in channel 1 feels colder compared to the other channels. Heater voltage is present at the socket though. Bad tube. I swapped the tube and problem solved! Slowly this console is coming together!

On to the switches! A look at the schematic will show the immense routing capabilities that these consoles have. Routing = switches... And lots of them. Push banks, throws, rotary, lots of switches. It took some time to trace out their workings. And following all of those tiny lines on the schematic is near impossible. I just went one switch at a time, testing as I went. Each switch had to be de-soldered, cleaned, taken apart in some cases, all to make them perform as new. Let's talk about relays. The monitor amp has three relays that control some of the monitor functions. These include utilizing multiple control rooms, switching between monitor speakers, and talk back capabilities. Being that we'll be using this console in one studio for recording only, I opted to remove the relays from the circuit. The monitor input is taken directly from the program amp's output transformer, and the control speaker will be wired directly off of the output transformer of the monitor amp. I won't need the talk back switching in the monitor section (for now) either. Otherwise, the monitor section will operate as designed. Eventually, I will restore the relay portion as well.

Holy cow... It's been over a year since I last documented the RCA console restoration! Let's recap! Ok, so since 90% of the wiring had been removed, it had to be replaced. Rewiring this was a daunting task and made me appreciate that much more what the assembly rooms at RCA must have been like in the 1940's. Wow! I started slow. 1 line at a time. Terminate one end, tag and terminate the destination end, check for continuity, repeat. 300' later, this is the result. When this is ready to install, I think I'll tie the lines with wax string like it would have been done originally. For now though, things are held in place with boring cable ties. So why red cable? Why not red cable? The original audio lines were Red. Also, it's nice to visually see a difference between audio (red) and power (black). In hind site, I should have chosen a different color for each stage. But this will work just fine. I work about 60 hours a week, and this restoration gets fit in when I can. In total, I'd guess the wiring harness took about 3 months of on and off again work to reinstall. So why did it take so long? Well, much of that time was spent fixing the last bozo's mistakes. In addition, there are a LOT of contact points. Several switches and buttons had to be repaired, and tested to get an idea of how they should be wired according to the schematic. A couple of the switches had 50 contact points. There was several hours right there of tedious removing of solder, fluxing, flowing, checking, testing, rechecking, repairing, retesting... You get the point. It might not look like much, but in total, there's about 300' of cable there.

So the 206 powered on fine. Vibrato went in great. The aux output and speaker jack went in without a hitch. I put an 8 ohm 5 watt dummy resistor on a switching jack for the external speaker. That way the output transformer still seem a load when this is used apart from the speaker base. The keyboard sounds great, but there's an intermittent crackle in the back ground. New caps should solve this. In went the new caps in the power supply. HUM.... POP! I blew a fuse... :( Not sure what happened. But this pcb is a PAIN to work on. It's really fragile. Probably has something to do with this. In disassembling the pcb from the chassis, I also checked the output transistor. One of them is shorted. There's my issue. When I get some time, I'll out the new transistors in and see where we're at.

A friend gave us a couple Wurlitzer 206 keyboards! He rocks! These are the same thing as the 200, minus the vibrato and with the addition of some routing/ monitoring functions for teacher-student use. I'll be converting this one to a 200 circuit, and making it "tour worthy." The plan is to chop the top from the base, add an aux output jack, add vibrato, lubricate every moving part, add an iec power socket, level the key bed, recap, and install new output transistors. The first thing to do was to make it playable. I disassembled it, cleaned out the 40 year old dust bunnies, took apart the action and removed the screws holding the keyboard to the base. Then took out each piece of the action to lubricate them. The keys fall nice and smooth now. Next came the iec power socket. I'll power it up in the next post.

While waiting for Mr. Genius to destroy our console, I decided to dig into a blue stripe kit I've been wanting to build for a while. This one is a Hairball Audio kit. Having not built an 1176 circuit before, the Hairball kit was a straight forward build. It arrived missing 1 transistor, which they shipped to me immediately. Calibration was simple too. How's it sound? Just like a blue stripe should! This gets a lot of use on vocal tracks here. I even use it on the occasional mono mix to add a bit of limiting before we hit the tape. I highly recommend Hairball Audio products!

Debacle...

I’m writing this a few months after the fact because I’ve been so busy. In trying to document this whole restoration process, I’ll include this hiccup with it. I really debated even mentioning this, but it’s part of the story, so I’ll include it here. I won’t mention anyone’s name… This whole situation still really pisses me off.

In an attempt to finish the console as quickly as possible, (I have several projects on the books waiting for its installation) I outsourced the rest of the work to an acquaintance of ours. We’ve bought some things from him in the past and he presented himself as someone with the knowledge, experience, and passion to do a great job on this console. We trusted he would do a great job.

I asked him if this was a project he’d be interested in. He seemed excited for the opportunity. Delivering it to him two states over was a pain, but we thought it would be worth it. Upon delivering it, we agreed to a loose budget, a time frame, and a possible gear trade for some or all of the work.

After the time frame for completion was up, I contacted him to see how it was going. “Almost done.” A little time later, we learned that he said the console was finished, but that it took considerably longer to complete and cost a lot more in parts than we talked about. “How much more???” He couldn’t give me an answer because he was out of town an not near his paper work… It was at this point that we started to get worried.

A few phone calls later, from both my brother and I, we finally got an answer. He wanted 3 times the budgeted amount - this included nearly $1500 in supplies and parts AND the piece of equipment we had agreed to trade!! We were shocked! Horrified! He never cleared these additional fees with us… Never gave us updates along way… And we were stupid enough to leave the console with him without some form of contract. We were forced to pay it, but obviously didn’t have that kind of cash sitting around. He was understanding enough to let us pay him about 60% of the total - everything we had in savings - , pick it up, and pay him the rest as soon as we could generate some income with it. Empty the savings accounts…

On three separate occasions, we made plans to pick up the console, and he canceled last minute. At one point, he said he would deliver it to us, but never showed up.

My brother - furious - called him to let him know when he would be picking it up and if he wanted his money he would be there.

The console was disconnected when he arrived to pick it up, so it couldn’t be tested. The next weekend I came to the studio to install it…

HORROR!

This guy had removed the entire wiring harness and replaced only the lines carrying voltage to the tubes. The complete audio path was ripped out save for the program - audition buss switches. Every routing function had been disconnected, the VU meter removed from the circuit, the audio terminal blocks removed, in addition, it was missing original parts.

We were angry… upset… Furious! He guaranteed that the console was passing clean audio in spec, and that it was fully tested and restored…. The console passed NO AUDIO what so ever! I was on the phone with him as soon as I found out. “This is perplexing”, his response. I gave him a couple hours to give me a date that he’ll be at my studio to finish the work. He didn’t get back to me until the next night and even then he only had a rough time frame in mind.

Days turned into weeks. His time frame for returning to do the work passed without any word from him. Throughout the whole process, this guy had terrible communication. Not being able to afford to wait any longer, we decided that it was time to cut our ties with him, loose out on the crazy amount of money we had just paid him for hardly any work, and that I would finish the work myself. Out of the blue one day, I got a voice mail message. “I’ll be there tomorrow to work on the console.” I don’t think so buddy. I had already begun finishing it myself. I wrote him an email documenting every point of his incompetence along this trial and told him that we were through trusting him. We wouldn’t be paying the balance, and we wouldn’t hold him to finishing the console. By this time, he had moved to the East Coast. I should also mention that the balance that we owed him equaled the cost of supplies and parts. I went through the console with a fine toothed comb - there is literally less than 10% installed of what he charged us for. One charge showed that he used an entire 500’ reel of cable at $1.00/ foot. I measured - he used about 70’ total of a reel of cable that costs $70.00 for 500’. You do the math. He duped us good.

We haven’t heard from him since sending the email. He took our money and ran. In hind sight, we should have taken him to court. I even talked to an attorney who assured me we had a case. But that’s not the type of people we are. This was a major blow to us both professionally and financially. But it did teach us some important lessons.

Conquer and divide. We took him out of the equation as are pushing through. This delays when I was planning on having it installed, but the journey is half the fun though right? It’ll make a great story to tell in the future…

Keep pushing on!

We took out the monitor amp to focus in on the preamp and program amp. With the new tubes installed, and all voltages checked out, it's passing audio! It's really distorted, but at least it's making sound! The integrated tube check meter tells me that the channel 3 1620, and both 1621's in the program amp output stage are not working. This is most definitely the cause of the distorted audio. Next steps? All of the wiring is 79 years old at this point and much of it is brittle and oxidized. I think the next step will be to assess the wiring harness.

While waiting for the new tube replacements to arrive, I made this. I kept this old peavey monitor around for acoustically re-amping things like snare drums and vocals. The theater just gave out so I decided to turn it into a sub kick. It does the job.

After a new power cord, on/off switch, and circuit modification (removal of the "safety" switch), the console was finally ready to power on! Here it is at my friend, Don's, shop. He's a broadcast engineer who built his first plate reverb in high school! His shop is full of restored radios, guitar amps, and and all sorts of other cool things from when Americans made great American designed products in America. I digress. the console was plugged in in to a variac and current draw was CLOSEY monitored until the console was at full power. No smoke! That's always a good sign. However, not everything was firing like it should. First problem was a bad rectifier tube. A replacement was here in a couple days. The next go around found that the DC voltages looked ok, but the filament supply was wacky. Something in the console was loading it way down. Lifting the connecting line between the power supply and the console brought it back. We found that some of the original wiring was bad inside the console. We also discovered that 2 of the 1620 tubes were bad. One was in the preamp module, the other in the program amp module. Replacements for those were ordered too. I can't explain how excited I was to see the VU meter light up for the first time. This has been a three year process up to this point and this is a big deal to me! It's the little things. Still no audio passing yet... That'll be next

I want to be like Sam, so I cut a panel for my Craftsman radio too. It'll get trimmed up once it's in the rack. Pictures to follow soon!

I needed the help from my friend, Don, to power on the console. It took a couple weeks to make it in to him, so in the mean time I made an Ampeg B-15n style circuit in a box. This one went to my church for the bass rig. Most pedals I make get a Jame's Brown lyric inside. My little secret...

My goodness good people! I totally let this blog get away from me! I apologize, but life has been crazy busy! I'll take the next few posts to catch up from where we left off. Before powering the console on, I had to make sure this power transformer was safe. I debated using a plasti-dip type product to insulate the crumbling insulation, or something else. I opted to use shellac. It went on well with a brush, I could get it down into the tight spaces and let it flow in, and I built it up with a few coats. All safe, now to power it on!

This morning I finished the complete recap. Hundreds or solder points re touched/ re flowed. 50 capacitors replaced. Several circuit modifications reversed. 2 cans of Deoxit poured into the switches. Everything has been cleaned up and spit shined... So to speak.. I'm waiting for the manual and schematics for the power supply to arrive. There's a potentiometer in the ps that's completely destroyed... No way to measure it and I won't know what the value is to order a replacement until I have a schematic. There's also some really rotten insulation on the power transformer right where the tap exits the winds. I'll be painting this area with a lacquer this week to insulate the exposed copper. Lastly, I need to make a door for the ps. The door, when closed, operates a momentary switch which is a safety power switch. Can't turn it on without a door. At the end of the week, I'll be taking the console and power supply to a friend for his input. A second set of eyes will be nice to go over my work and offer some knowledge. From there we'll power it up and bring everything back to spec! Keep with me! Nearing the finish like with this restoration!

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