Phase Linear 700 Part 2 - The Power Supply

[@garygranato9164]

thank you very much for the video tony, us hobbyists and noobs really appreciated the knowledge you pass on.

[@williamchow1624]

It is all in the details. That is the difference between a hack and a perfectionist.

[@johnvanwinkle4351]

I enjoy your narration through your videos….

[@poormanselectronicsbench2021]

Looking good! I think the only thing I would do different ( if, you didn't plan to do it) is, wire the line / mains power heat sink thermal switch into the relay coil power circuit for your soon to be installed speaker protection relay, instead of the mains / line power. I never did like the thought of having that extra wire on the line power, going to places it really didn't need to, and if it was wired into the speaker protect relay coil, it would have a much smaller load to switch, and would still afford the protection of disconnecting the load and letting things cool down before letting the relay close again to reconnect the speakers.

[@eykensf]

25:00 Hi Tony, That very thin wire has a use. It is a fuse, as shown in your scheme. In later 400 the have installed a real fuse. It is so a good idea to install an holder and a fuse on the yellow or orange white. 500mA is what PL installed in the series two production year 1982. The rectifier on the VU board sometimes break and in this case a fuse will be more secure. Greetings from Belgium, Flip

[@eykensf]

white must be wire - excuse

[@xraytonyb]

I know I mentioned this in the video. I hope it didn't get edited out. :( I removed the fuseable link (that's what we called them at the time) and replaced it with an inline fuse holder. Thanks for the comment!

[@eykensf]

You did that and it is in your video, just the 2A is in later versions just a 0,5 A fuse. Very good story - you are an expert!

[@PossibleAudio]

I really enjoyed this video. Thanks Tony!

[@jaybats7865]

You’re the best! Thanks for the fun Tony, can’t wait for the next installment as always 👍 best wishes for your surgery and recovery

[@kenielsen]

Exactly how bypass caps are supposed to be used Tony 👍👍👍 looking forward to the continuing work on this amp😊

[@unwrittenrulelive]

Hi from England,back in the day pink Floyd used racks and racks of these amps to run their pa system , love your work and passion for audio please keep it up

[@robburbrink8277]

Looking forward to the next video Tony! Loved watching the power supply rebuild. learning so much. I like the talking video idea too. keep up the amazing work and thank you so much for making these. good luck w the health procedure! best wishes.. RB

[@anthonysmith7331]

Great stuff,Tony.I have learned a lot from your videos.I have a great love for vintage audio equipment.Keep those great vides coming.

[@zambrano966]

Hola Tony, solo a forma de comentario los amplificadores Marantz y Sansui le colocan una resistencia de 2.2 Kohm, 3 vatios en paralelo a los condensadores principales para descargar los condensadores, es una practica muy común en esas marcas. por citarte un ejemplo el AU-717 de Sansui le colocan una resistencia de 3.3 Kohm 2 vatios y en el amplificador Marantz modelo 300DC le colocan resistencia de 2.2 Kohn 3 vatios, el Marantz maneja un voltaje de +/- 70 voltios y el Sansui maneja un voltaje de +/- 56 voltios. Solo te quería comentar, como veo que el lado positivo se descatga por el circuito de arranque suave , pero el negativo no, seria una solución para que ambos se descargaran igualmente.

[@xraytonyb]

¡Gracias por la sugerencia! Agregaré una resistencia en el lado negativo para drenar el capacitor al mismo ritmo que lo hace el circuito de arranque suave en el otro lado. ¡Gracias!

[@Sunnbobb]

excellent video

[@nestormejias7208]

Agradecido con excelente aporte amigo Tony. Saludos desde Venezuela.

[@tommybewick]

Oh my God Pink Floyd is my favorite band! I'm seeing David Gilmore in New York City in November. The last time I saw David Gilmore was in 1984 in Buffalo. I can't wait!! I love the history of these amps with Pink Floyd.

[@schorse1000]

I'm jealous now...

[@ZiGLH]

Hello, you have one more follower. Your channel is so interresting. Thanks for that!😊

[@KSWong-xi8cd]

This video is ultra helpful for electronics beginners like me. Cheers.❤

[@stevent3450]

I remember back in the early 80's I had a friend who owned a small nightclub disco bar who used one of these amps only for the bass scoops, I was still in school but working at a Sony service center to get experience, well he was frantic and got a hold of me to see if there was anything I could do, I said sure, I thought it had shorted outputs but was NOT what I found was the primary AC input of the main transformer was shorted, so I opened it up and found that only one part of the Ac windings were shorted, so I disconnected the shorted winding from the other and it worked and gave back to him and told him, he said it worked great but didn't seem to have the power, of course it was because of only 1/2 the primary AC input was disconnected ( me)

[@Sans_Solo_]

Tony, your PF story reminds me of the "Wall of sound" John Curl and others did for a Grateful Dead tour. Cool system

[@davidbailey6350]

Thanks Tony, take care of yourself.!

[@sebastian_harnisch]

47:30: Great explanation, I have one minor addendum. More importantly in the context of higher frequencies: Wires add inductance. The reactance, i. e. the inductive part of the impedance, increases with frequency. Meaning the impedance increases with frequency too. Even relatively small capacitors have a low ESR at high frequencies, but because of the reactance - not so much the resistance - they should be connected via a low impedance path (again: reactance dominates). What really decreases the inductance: a) use shorter wires, b) decrease the loop area (i.e. route the current return path close by).

[@schorse1000]

It comes with solder for repairs? I didn't know that Tektronix also made audio amps.😜

[@greengrayradio1394]

Silver content also? ;)

[@andymouse]

@@greengrayradio1394 Yeah that was back in the day !

[@greengrayradio1394]

@@andymouse I have two ofthose small white reels with Tek solder. Nice to have when soldering to silvered ceramic caps

[@andymouse]

@@greengrayradio1394 :)

[@haraldlonn898]

Soo whould like to have my Flame 400 mark I to be safe for my second best speakers ever made in the 80' . The big L100gi. It sounded great for 35 years ago but now I just don't want to test if it works. Thanks for your great videos.

[@mfr58]

Maybe your amp was a Pink Floyd modded one, with the plastic bag relay.....

[@petertimp5416]

Thanks Tony!

[@douglashoff95]

If I remember correctly the first series of 700's (with regular meters) used all NPN (PL909 or XPL909) transistors. Looks like the Series 2 went to a full complementary circuit.

[@jdmccorful]

Great info passed off here. Thanks for your work in explaining things so clear. Love the "solder and chats"!

[@Cavemannspace]

Still enjoying all your videos, however, somehow I missed your capacitor discharger video. I'll be looking for it on your channel as I would like to build one. Sure, I've been using a resistor and alligator clips, but I'd like to see the discharge. So I'm assuming you did make a video on the capacitor discharger. If not, I'd like to see at least a schematic. Thanks!

[@xraytonyb]

I didn't do a video on it. Maybe a good idea for a future video?

[@Cavemannspace]

@@xraytonyb I know you would have at least one very interested viewer. I'd like to make one like it. Thanks for the reply. Hope all goes well with your surgery and recovery. Don't over do it.

[@jefftobin4034]

Tony, regarding the bypass caps at the main filter caps, I thought they were to suppress any RFI that may come in on the line. And for that purpose, you would want them as close as possible to where the mains enter the unit. Additionally, I often see (I work on mostly Sansui gear) small non-polarized caps across electrolytics, mostly in the phono preamp and tone circuits.

[@poormanselectronicsbench2021]

Smaller value bypass caps will help with RFI suppression, or any frequency interference, but for higher frequency suppression, they do work better when placed closer to the end path of the circuit they are powering / connected to. Dave at the EEVBLOG youtube channel did a good practical example where he introduced noise onto a circuits power path, and moved the small bypass cap into different locations in the path. The closer he got to the circuit, the more noise that bypass cap suppressed.

[@erikdenhouter]

You can see the long wire to the end device as an antenna. So closest to the device the cap will take out most interference. Does not imply that in case of long lines putting two caps, at the beginning and end would be bad.

[@poormanselectronicsbench2021]

@@erikdenhouter The point of RF coming in through the power line is more relevant in a transformerless device such as a "All American 5" radio, which, does have a cap across the line. Once the line voltage gets into the transformers primary, there's practically little to no chance of RF getting passed on, unless your neighbor still has a 2KW linear amp on his CB with a Moonraker 6 pointed right at your house. I'm still in agreement with Tony's evaluation of where to place any bypass caps, and there are already C110, and C111, each a 0.33uF cap bridged to chassis common to properly serve as a higher frequency bypass component.

[@roroseppel2077]

This is quite a dangerous amp with 2 * 100 VDC inside !

[@haraldlonn898]

I don't remember exact but BD 55 or something, it is old TV high power transistors for the transformer and I changed all the xpl909 on the one side and it did work just fine. Now I don't trust the amp for my speakers. Just a note from me.

[@zulumax1]

Love the solder and chat sessions! Good information about bypass capacitors, and yes I think they should go closer to the load side on the circuit board, makes sense. I am working on a Hafler D-200 amp for my son presently. Someone put film bypass capacitors across all the electrolytics on the PCB, as well as the main power cans. They also changed the input NP electrolytic 10mfd 16v to a film cap, which may go back to original, haven't decided on that. There are also 0.1mfd film bypass caps on the speaker fuses, but that is stock. Here is the headscratcher however: They changed the 20 gauge white/black twisted set wires that run from the input RCA jacks to the PCB with 12 gauge monster speaker cables with no twist! Why??? That makes no sense to me. Why would you do that?

[@paulb4661]

AudioFile inspired mod I'd think; perhaps the twist was deemed a detriment, the electrons getting confused by rapid changes in direction, losing the minute detail in the process?

[@Satchmoeddie]

De-Ox-It is about 93% odorless paint thinner, 3% dielectric grease & a mystery petroleum based solvent, and 4% propellant compounds. When De-Ox-It implemented that leaky spray can straw, I put some Dow Corning silicon grease in odorless paint thinner (pure mineral spirits) and put that in a rechargeable spray can. I don't use the red De-Ox-It anymore. By cleaning with 100% mineral spirits, then a small spritz of the grease dissolved in mineral spirits I am not saturating that fiber board in oil.

[@nanocamp-audio]

Silicone grease has an insulating effect and does not seem good for switches and pots.

[@stevenholquin2127]

I Have The 700-B Black Face

[@andrewcastellane7802]

alright!

[@joe841984]

Hello Toni you replaced the bridge rectifier with a new one should this be done if your installing new filter caps or would it be ok to leave the original so long as its still working ok and could you post a part number for the rectifier you used thanks George..

[@davewilliams5932]

Hi xraytonyb. On a pioneer737 power amplifier board, does the two PNP transistors in the middle of the board or at the end of the board?.

[@mmorrison6775]

how do you keep your bench so clean it may be messy to you however my bench is 2-3 times messier than yours is all ways even after i straighten it up

[@terrykinch8248]

What tool did you use to bleed down the 9k microfarad caps at the 1:00:00 mark?

[@MrJohnBos]

The people who bought Accuphase equipment back in the day had more money than brains. IMO, Accuphase components were way overpriced for what they actually were.

[@andymouse]

Yeah a bit like the Quad 405 ! just check out the schematics.

[@seanobrien7169]

Looks like syd barrett may have worked on that one! 🙄

[@schorse1000]

🤣🤣🤣

[@xraytonyb]

The amp has become comfortably numb

[@steveh1273]

According to the circuit diagram, the PS caps are 22,000 uf each, why did the gray ones have 9800; and the Cornells you put in were 11000?

[@xraytonyb]

The original caps were 9800uF/100 volt. My original intention was to install 22,000uF/100 volt, similar to what Pioneer uses on similar sized amps, as the transformer in this amp could easily handle it. As it turned out, the power supply voltage was about 103 - 104 volts, which exceeded the maximum voltage rating of the 22,000uF caps. The old 9800 uF caps were also operating above their rated voltage, but I suspect they were more conservatively rated. The 11,000uF/150 volt caps I settled on were the closest ones I could find in value that would fit as a drop-in replacement and they were also high quality. I'm pretty sure I explained this in the video.

[@jojoanggono3229]

​@@steveh1273 I tried Cornell power reservoir cap a few years back. They sounded horrible. Couldn't recall the model code. Original cap is Nichicon, 16.000uF 100V. I just couldn't find Nichicon with equivalent capacity, voltage back then.

[@steveennever9905]

5:16 "that probably wouldn't work for me" - No, it wouldn't. Lowest common denominator, my friend. As little information as possible for minds that absorb very little. Replace everything else with loud noises, pretty lights & repetitiveness. ;-)

[@garypoplin4599]

7:41 - By “hard work” you mean taking the pot completely apart and rubbing down the track with IPA, right?

[@Joetechlincolns]

@6:30 Phenolic?

[@xraytonyb]

That's it! Had a senior moment ;)

[@marcelr1605]

Hi Toni, I think your content is too intellectual for massive click counts. A good electronic content maker in Germany told the same phenomenon as you, for a time. He was annoyed that stupid shit, like free energy or hifi voodoo things become so much attention. Most people today are don't interested in really since things. They can't do anything with this. It's too lonely. Here in Germany we had until the 2000's lots of science kits for kids. Everything is gone. No one wants to study courses in science anymore. But all a busy with there smartphones everyday. The new world. Kind regards from Germany Marcel

[@davidgriffin79]

4:53 Demographics: the number of views is inversely proportion to how far to the right of the I.Q. Normal Distribution curve, the viewer is.

[@andymouse]

Could you simplify this please ?

[@davidgriffin79]

@@andymouse The number of views is inversely proportional to the intelligence of the channel content: i.e., dumb people like dumb things.

[@queputaleche]

hahaha, we have the same TY feed, I saw the same video of Pink Floyd past week. I was thinking about make you the seggestion of making the Pink Floyd mod to this amplifier

[@eddys.3524]

To go viral, perhaps next time try something like : Million watt amp burned my house down. my2cts

[@xraytonyb]

Don't forget, it has to include someone making a stupid surprised look on their face with their mouth agape ;)

[@eddys.3524]

@@xraytonyb That indeed would be a usefull addition.