Pass DIY F5 Amp Build

M

MrBoat

Audioholic Samurai
@MrBoat
I have likely shown you this link before, but I have been really looking at the builds from the Signal Transfer Company! These are the designs of Douglas Self, he has many commercial designs, and several books on audio electronics construction. I don't think he has any of the crackpot designs like Pass does ;)

Thank you for the keys to yet another rabbit hole.
 
M

MrBoat

Audioholic Samurai
Here are the boards (one each channel) for the Honey Badger amp. This one, ups my level a little more. Have to wind some inductors, and the sheer number of components. This is a more powerful amp than what I have built to date. Already have the transformer on the way, but do not know when I will actually build it. I may spend the next year or so gathering the parts. Or, I may get a wild hair and just go to town on it.

All of these things I have to feel like doing, or I won't until I really want to. This F5 sat for well over a year. I had no idea what all I had collected for it. I got stoked when I saw I already had the transformer and the rear panel kit of parts. That was all the trigger that I needed to get moving on it.

This Honey Badger will likely be the last A, or AB type that I build. It's the Class D stuff that has my interest more than anything else, these days. Any other "type" of sound can pretty much be had via speakers.

 
Eppie

Eppie

Audioholic General
You guys have it so easy now with the circuit board services available. :D I should post pics of the parametric eq I made many years ago. Masking tape and acid to etch the copper and no fancy silk screen for part layout. Looks a horrid mess compared to these builds.
 
slipperybidness

slipperybidness

Audioholic Warlord
You guys have it so easy now with the circuit board services available. :D I should post pics of the parametric eq I made many years ago. Masking tape and acid to etch the copper and no fancy silk screen for part layout. Looks a horrid mess compared to these builds.
The better DIY approach is to print a projection/mask on acetate (like for the old overhead projectors), then use that and a hot clothes iron to transfer the ink onto the Copper plate as the mask.
 
highfigh

highfigh

Audioholic Slumlord
Yeah, let me know it you find very good flush cutters. I have gone through several of those over the years. Once they start getting worn with normal use, they get demoted to softer plastic snipping only.
Are you resharpening on the inside bevel, or the flat surface? If you sharpen the flat face, they'll be at least as sharp as when they were new.
 
highfigh

highfigh

Audioholic Slumlord
You guys have it so easy now with the circuit board services available. :D I should post pics of the parametric eq I made many years ago. Masking tape and acid to etch the copper and no fancy silk screen for part layout. Looks a horrid mess compared to these builds.
A company called Bishop Graphics used to sell stick-on circuit board 'parts' for PCB layout on Mylar, like traces, soldering pads for the pins, symbols where various components would go, ground plane, etc- this was used to create the mask for the photo-resist/etching stage and could be scanned for fitting the desired size of the boards. They came in different widths and colors, to designate power supply, ground, circuit path, etc.


Now, it's all done on those new-fangled computin' things.
 
Eppie

Eppie

Audioholic General
The better DIY approach is to print a projection/mask on acetate (like for the old overhead projectors), then use that and a hot clothes iron to transfer the ink onto the Copper plate as the mask.
Yes, I have used photo resist as well but this was an early project from a magazine. The specs on the eq were actually pretty good. I'll have to dig through my files and see if I still have the schematic and specs. I only built one channel to test with a bass guitar amp but I think the schematic called for two discrete channels any way.
 
Eppie

Eppie

Audioholic General
Now, it's all done on those new-fangled computin' things.
LOL ... yeah, I wouldn't go back to manually laying down traces except for the most simple circuits. The software was prohibitively expenses when I was a repair tech so it's great to see the DIY community have access to all of these tools that allow you to make professional quality boards without breaking the bank.
 
highfigh

highfigh

Audioholic Slumlord
LOL ... yeah, I wouldn't go back to manually laying down traces except for the most simple circuits. The software was prohibitively expenses when I was a repair tech so it's great to see the DIY community have access to all of these tools that allow you to make professional quality boards without breaking the bank.
A friend was contacted by someone we went to college with, to layout some boards for a cardiac monitor that had a button which was pressed when the symptoms began, but had been recording the patient's pulse info the whole time, so it would save a few minutes and continue recording. We used the Bishop's Graffics decals and it was a good way for me to learn about electrical circuits, since that's not what I studied. It was interesting, but working over the light box was pretty grueling, after a while.

Years later, I went to a medical office to look into installing some distributed audio equipment and saw one of the monitors sitting on the ledge of a window, so I asked about it- the person asked how I knew what it was and I explained about the work we did in laying out the boards. My boss at the time was there and he had no idea I had been involved.
 
M

MrBoat

Audioholic Samurai
You guys have it so easy now with the circuit board services available. :D I should post pics of the parametric eq I made many years ago. Masking tape and acid to etch the copper and no fancy silk screen for part layout. Looks a horrid mess compared to these builds.
I have built some P2P projects like the gain card clone, but it was rather crude and ugly looking. A good exercise in understanding schematics/circuits, though. As with so much of DIY, just knowing you can if you have to, is enough, sometimes. Most of these DIY projects are a collaboration of ideas than have been discussed into their current version, on chat forums. Watching them evolve over time with input from so many bright minds is fascinating to me.

Half the time, I start out buying the boards just to own a copy of them and maybe never do anything with them. I do feel fortunate having access to the affordable resources that we do have though. I went to electronics school for two years back around 1980. An LCD TI calculator was a big deal. My instructor instead, still used a slide rule for all of his calculations. At any rate, I have since forgotten just about everything except how transistors, diodes and other components work. Well, that and Ohm's law. I hated electronics then. I have since warmed up a bit to it and whatever training I may have retained like, how to solder.
 
slipperybidness

slipperybidness

Audioholic Warlord
Are you resharpening on the inside bevel, or the flat surface? If you sharpen the flat face, they'll be at least as sharp as when they were new.
I have built some P2P projects like the gain card clone, but it was rather crude and ugly looking. A good exercise in understanding schematics/circuits, though. As with so much of DIY, just knowing you can if you have to, is enough, sometimes. Most of these DIY projects are a collaboration of ideas than have been discussed into their current version, on chat forums. Watching them evolve over time with input from so many bright minds is fascinating to me.

Half the time, I start out buying the boards just to own a copy of them and maybe never do anything with them. I do feel fortunate having access to the affordable resources that we do have though. I went to electronics school for two years back around 1980. An LCD TI calculator was a big deal. My instructor instead, still used a slide rule for all of his calculations. At any rate, I have since forgotten just about everything except how transistors, diodes and other components work. Well, that and Ohm's law. I hated electronics then. I have since warmed up a bit to it and whatever training I may have retained like, how to solder.
My path down electronics was basically, "hey these guys are doing it, surely I can too!" The nice thing about electronics (and science in general) is that you learn a set of rules, then everything "must" obey those rules and laws! If something seems to be violating those rules, then something has broken, gone out of spec, or some other gremlin must be at play.

In science, you build a theory or a world view, then collect data. If the data does not line up with your theory or world view, then you must adjust your theory or world view, then retest.

The answers are ALWAYS in the data. If not, then you either are not interpreting the data correctly, or you have the wrong data set. That's where my value for my employer comes in--Did I interpret this data properly? What does this unexpected data tell us? Do we even have the right data?
 
M

MrBoat

Audioholic Samurai
Are you resharpening on the inside bevel, or the flat surface? If you sharpen the flat face, they'll be at least as sharp as when they were new.
I re-sharpened mine, but the handles and the actual pivot joint are shot so the cutting edges don't always align. I like the Lindstrom cutters the best so far. The Knipex are good, too. I keep a larger set for thicker wire and leads, though. Before, I was always pushing the limits and this time I catch myself and opt for the appropriate tool.

 
Eppie

Eppie

Audioholic General
I'll try not to highjack MrBoat's thread but as long as we're talking about getting into electronics...

I kind of fell into the trade while going through uni. I had studied electronics in high school and even got to work with some low powered laser projects. Had a knack for it as a teen. While looking for summer employment after high school, a friend had started a business installing car audio in the rear of a stereo and TV store. I would come by after looking for work in the morning and started helping out with installations and then got involved with repair work. We eventually out grew the space and he got his own store selling car audio and doing stereo and TV repair. I hated repairing TVs :) but liked to work on any kind of home or car audio equipment. We became the local Clarion dealer and authorised service depot for several brands. I also took some electrical engineering courses in uni but was basically self taught for repairs. We even had the Garry Robertson DJ service from out west bring us their gear for local DJs because they built their own equipment and there usually were no schematics to work from. I also got to service local truck weighing stations (on the side of the highway) when they first introduced sensors in the roadway to count axles and and get rough weight measurements. It fed a computerized system that ran the data and then used overhead signs to direct the trucks into the proper lanes. I was one of the few local techs at the time with both electronics and computer experience to diagnose those systems.

That job also helped feed my love for hi-fi. How can you resist when buying wholesale. ;) Mark up could be 50% to 100% back then so even during uni I managed to scrape up enough to get me started. I think my car audio system was worth more than the car. :D First home speakers were a pair of Electrovoice Interface Series II like these https://www.ebay.com/itm/264851715934. I still have them but the woofers need to be refoamed.
 
M

MrBoat

Audioholic Samurai
I'll try not to highjack MrBoat's thread but as long as we're talking about getting into electronics...

I kind of fell into the trade while going through uni. I had studied electronics in high school and even got to work with some low powered laser projects. Had a knack for it as a teen. While looking for summer employment after high school, a friend had started a business installing car audio in the rear of a stereo and TV store. I would come by after looking for work in the morning and started helping out with installations and then got involved with repair work. We eventually out grew the space and he got his own store selling car audio and doing stereo and TV repair. I hated repairing TVs :) but liked to work on any kind of home or car audio equipment. We became the local Clarion dealer and authorised service depot for several brands. I also took some electrical engineering courses in uni but was basically self taught for repairs. We even had the Garry Robertson DJ service from out west bring us their gear for local DJs because they built their own equipment and there usually were no schematics to work from. I also got to service local truck weighing stations (on the side of the highway) when they first introduced sensors in the roadway to count axles and and get rough weight measurements. It fed a computerized system that ran the data and then used overhead signs to direct the trucks into the proper lanes. I was one of the few local techs at the time with both electronics and computer experience to diagnose those systems.

That job also helped feed my love for hi-fi. How can you resist when buying wholesale. ;) Mark up could be 50% to 100% back then so even during uni I managed to scrape up enough to get me started. I think my car audio system was worth more than the car. :D First home speakers were a pair of Electrovoice Interface Series II like these https://www.ebay.com/itm/264851715934. I still have them but the woofers need to be refoamed.
I inadvertently got into electronics and electrical working on electric motors, of all things, after I went to school for electronics and hated it. I was always good at figuring out car audio as a teen. Mostly from getting second hand items before plug and play became a thing. I would often have to lift the covers and visibly see what the harness wires went to after doing the same with receivers and whatnot that had wiring diagrams intact. Welding for a living, throws you into electronics whether you want to or not because, authorized service centers are far and few between for even the biggest brands, and it takes weeks, or even months to get warranty repairs done. My boss, is an EE (over 35 yrs) with a major national defense contactor and these types of topics come up. I somehow manage to hold my own but, damn, this is some dry stuff. Also did a couple years working on home appliances, so I was always kind of circling that electronics drain.
 
M

MrBoat

Audioholic Samurai
My path down electronics was basically, "hey these guys are doing it, surely I can too!" The nice thing about electronics (and science in general) is that you learn a set of rules, then everything "must" obey those rules and laws! If something seems to be violating those rules, then something has broken, gone out of spec, or some other gremlin must be at play.

In science, you build a theory or a world view, then collect data. If the data does not line up with your theory or world view, then you must adjust your theory or world view, then retest.

The answers are ALWAYS in the data. If not, then you either are not interpreting the data correctly, or you have the wrong data set. That's where my value for my employer comes in--Did I interpret this data properly? What does this unexpected data tell us? Do we even have the right data?
@MrBoat
I have likely shown you this link before, but I have been really looking at the builds from the Signal Transfer Company! These are the designs of Douglas Self, he has many commercial designs, and several books on audio electronics construction. I don't think he has any of the crackpot designs like Pass does ;)

I started to check this site out. So far it is pretty interesting. Will read more over the weekend.
 
highfigh

highfigh

Audioholic Slumlord
I have built some P2P projects like the gain card clone, but it was rather crude and ugly looking. A good exercise in understanding schematics/circuits, though. As with so much of DIY, just knowing you can if you have to, is enough, sometimes. Most of these DIY projects are a collaboration of ideas than have been discussed into their current version, on chat forums. Watching them evolve over time with input from so many bright minds is fascinating to me.

Half the time, I start out buying the boards just to own a copy of them and maybe never do anything with them. I do feel fortunate having access to the affordable resources that we do have though. I went to electronics school for two years back around 1980. An LCD TI calculator was a big deal. My instructor instead, still used a slide rule for all of his calculations. At any rate, I have since forgotten just about everything except how transistors, diodes and other components work. Well, that and Ohm's law. I hated electronics then. I have since warmed up a bit to it and whatever training I may have retained like, how to solder.
We were finally allowed to use calculators in high school in late- 1975 and that's fortunate because I had a Physics final. After HS, calculators could be seen hanging from the belts of many Engineering students who also wore gray or black work pants, work shoes with white socks and white button-down short-sleeved shirts with fully-loaded pocket protectors and either flat-top or crew hair cuts. That was Geek Central.

Some of the classes had a huge slide rule over the chalkboards- must have been 6' long.
 
M

MrBoat

Audioholic Samurai
A little progress. Hiccups like this tend to sidetrack me for a few days at a time and onto something else that needs attention for awhile. Hookup wires. I could not (relatively instantly, at least) get a definitive answer about using shielding beyond say, twisted pairs seeming to apply to almost everything DIY audio. Input wiring sharing a space with a relatively large toroidal transformer seemed to be begging for a gremlin to be added to the mix so I figured shielded wire would be a better option. I noticed they used it on the inputs of a desktop system I had, only because grandkids stepped on the subwoofer and ripped the strain relief loose, and the shielding, which was also the ground and I had to redo it. Anyway, I saw where some used it, some didn't, and some made up some other sort of braided arrangement of wires. Then I went to go find some shielded wire. They add other specific purpose names to it like "guitar hookup wire."

But, leave it up to youtube to have a video of someone with the same complaints making their own and that seemed like a great, long term solution to this issue, being, I will likely be messing with electronics from here on out. At least now I can move on with this project again.

1/8" flat tinned copper braid, using a bamboo skewer to make a tube of it.


Sliding a piece of 22AWG, silicone covered wire into the braided tube. I did end up smoothing the braid out with the side of the skewer until it covered the wire smoothly and completely. In other words, I could not see any of the color of the insulation thru it after.


Followed by a section of 1/8", polyolefin, 2:1 heat shrink tube.
 
Last edited:
M

MrBoat

Audioholic Samurai
I think you just broke my brain, @MrBoat .
Love your solution. As always, very nice work.
Just me learning how to overkill that, which I don't have the attention span to be certain of. Even if I were certain of it today, I will have forgotten it all 6 mos from now. :D
 
ryanosaur

ryanosaur

Audioholic Warlord
Just me learning how to overkill that, which I don't have the attention span to be certain of. Even if I were certain of it today, I will have forgotten it all 6 mos from now. :D
I probably woulda just stripped the ends off an RJ6 Coax and called it a day. (Assuming it fit!) ;)
 

newsletter
  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top