Amp Camp Amp

[MrBoat]

Ordered the PCB's. Seems the kits have been out of stock for awhile. Was/is (?) supposed to be an upgrade in the works.

Either way, I bought it on a whim. I probably should have checked to make sure I could get all of the parts for it first. I don't really have the want for point-to-point wiring these days and like the looks of a neat PCB.

The enclosure is probably more of what will make it mine. I am an aluminum fabricator/welder by trade. Now watch, I'll end up the crudest looking rig all Frankenstein'd on a shoebox, or something.

I know the topic for this is over at diyaudio, but figured to see if anyone here has built one, or whatever other amp they may have built. I still have to order the other parts but have just been lazy because as mentioned, this is on a whim and maybe get some inspiration here, if what happened with speakers is any indication.

Finally, I like building/using audio stuff and I don't need anymore speakers/subs so this may do it. If the bug catches, I can fit a lot more electronics on shelves than speakers. The other thing being, I know I am not going to 'buy' anymore factory speakers. What I would still have to buy though is amps or AVRs. It would be nice to know I could cobble together a simple, low powered amp with some sensitive speakers and get by with some decent sounds as a different kind of futureproofing and avoiding that ultra-expensive. . . . upgradeitus.

 

[highfigh]

Ordered the PCB's. Seems the kits have been out of stock for awhile. Was/is (?) supposed to be an upgrade in the works.

Either way, I bought it on a whim. I probably should have checked to make sure I could get all of the parts for it first. I don't really have the want for point-to-point wiring these days and like the looks of a neat PCB.

The enclosure is probably more of what will make it mine. I am an aluminum fabricator/welder by trade. Now watch, I'll end up the crudest looking rig all Frankenstein'd on a shoebox, or something.

I know the topic for this is over at diyaudio, but figured to see if anyone here has built one, or whatever other amp they may have built. I still have to order the other parts but have just been lazy because as mentioned, this is on a whim and maybe get some inspiration here, if what happened with speakers is any indication.

Finally, I like building/using audio stuff and I don't need anymore speakers/subs so this may do it. If the bug catches, I can fit a lot more electronics on shelves than speakers. The other thing being, I know I am not going to 'buy' anymore factory speakers. What I would still have to buy though is amps or AVRs. It would be nice to know I could cobble together a simple, low powered amp with some sensitive speakers and get by with some decent sounds as a different kind of futureproofing and avoiding that ultra-expensive. . . . upgradeitus.

If you're a fabricator, why not use billet Aluminum and a milling machine?

 

[ski2xblack]

Speakers are more fun as DIY projects than amps, IMO. There is a lot more going on in electro-mechanical transducers than amps, which, at least ideally, just amplify. But to build an amp that performs well and has sufficient power is not a simple or inexpensive affair, and if you spend the money to build such a thing you end up with an amp that's pretty much audibly indistinguishable from most others.

So kudos on trying out that one, a single ended oddball from Nelson Pass, and something you could likely pick out in a blinded comparison with conventional amps. That amp's inherent lack of crossover distortion, 2nd order dominant distortion profile, and output impedance should provide results akin to a SET amp. (That seems to be the target with quite a few of Pass' designs.)

At 5 watts, you'll probably be limited to using it with your Tempests, at least if you want any sort of appreciable volume. It should also work well with those speakers you built using wide band drivers as well, but probably not for rockin' the house.

If it's been a while since you slung the solder, practice on something disposable beforehand.

And I'm as curious as to what you'll build to house it as I am about the amp itself. Keep us posted of your build progress and listening impressions.

 

[MrBoat]

If you're a fabricator, why not use billet Aluminum and a milling machine?

There's a welders joke along the lines of; "Can't you just buy that?" Milled billet is the obvious choice and even more so now that CNC is running everything and to be honest, I'm tired of it. To the contrary, I draw my own prints and patterns by hand and make 99% of what I weld like that too.

This is a cheap amp which is part of it's design criteria. Now if I would fashion a plug by hand and have it cast instead, that would be more fabricator-ish by my thought.

 

[MrBoat]

Speakers are more fun as DIY projects than amps, IMO. There is a lot more going on in electro-mechanical transducers than amps, which, at least ideally, just amplify. But to build an amp that performs well and has sufficient power is not a simple or inexpensive affair, and if you spend the money to build such a thing you end up with an amp that's pretty much audibly indistinguishable from most others.

So kudos on trying out that one, a single ended oddball from Nelson Pass, and something you could likely pick out in a blinded comparison with conventional amps. That amp's inherent lack of crossover distortion, 2nd order dominant distortion profile, and output impedance should provide results akin to a SET amp. (That seems to be the target with quite a few of Pass' designs.)

At 5 watts, you'll probably be limited to using it with your Tempests, at least if you want any sort of appreciable volume. It should also work well with those speakers you built using wide band drivers as well, but probably not for rockin' the house.

If it's been a while since you slung the solder, practice on something disposable beforehand.

And I'm as curious as to what you'll build to house it as I am about the amp itself. Keep us posted of your build progress and listening impressions.

The Tempests are what I had in mind. This is just to build it. I don't need the amps for any practical purpose but, seems that every time I try something a little off the wall like this, I end up liking it for what it is and end up being somewhat surprised by it. I do like the idea of it being a Pass design and there is a novelty in that somehow as well. I also dig the open source aspect of it as well.

I don't rock the house with the little wide band speakers as it is. They just sound sweet at what they do. Most I ever push those is up in the mid 80's db range. That would be cool if the amps somehow ended up working with those speakers but those need a sub as well. I reckon I could use the pre-outs on the AVR.

I agree with you about what amps contribute to the overall sound. I have no biases to that end. I've been pretty happy with all of the amps I have owned and it has been indeed, the speakers that have made the biggest difference.

I did order the rest of the parts and a friend of mine who is a tube head, of all things, happens to have matched pairs of the now obsolete Toshiba JFETs, that he says I can have, along with some other hardware, wire and whatnot.

 

[highfigh]

There's a welders joke along the lines of; "Can't you just buy that?" Milled billet is the obvious choice and even more so now that CNC is running everything and to be honest, I'm tired of it. To the contrary, I draw my own prints and patterns by hand and make 99% of what I weld like that too.

This is a cheap amp which is part of it's design criteria. Now if I would fashion a plug by hand and have it cast instead, that would be more fabricator-ish by my thought.

CNC is great, as long as it has been programmed correctly.

Only casting it? A real DIYer would mine the ore and process it before even thinking of casting anything.

 

[MrBoat]

CNC is great, as long as it has been programmed correctly.

Only casting it? A real DIYer would mine the ore and process it before even thinking of casting anything.

Nah. There's plenty of aluminum above ground to recycle. We have 55 gal drums of the stuff. Besides, most of the aluminum is coming out of Africa these days, anyway. I thought about welding up a heat sink out of some of the extrusions we use and some flat bar but I don't know if I feel like doing that unless I come up with something unique that I like. I liked the kit they had for it.

 

[ski2xblack]

The Tempests are what I had in mind. This is just to build it. I don't need the amps for any practical purpose but, seems that every time I try something a little off the wall like this, I end up liking it for what it is and end up being somewhat surprised by it. I do like the idea of it being a Pass design and there is a novelty in that somehow as well. I also dig the open source aspect of it as well.

I don't rock the house with the little wide band speakers as it is. They just sound sweet at what they do. Most I ever push those is up in the mid 80's db range. That would be cool if the amps somehow ended up working with those speakers but those need a sub as well. I reckon I could use the pre-outs on the AVR.

I agree with you about what amps contribute to the overall sound. I have no biases to that end. I've been pretty happy with all of the amps I have owned and it has been indeed, the speakers that have made the biggest difference.

I did order the rest of the parts and a friend of mine who is a tube head, of all things, happens to have matched pairs of the now obsolete Toshiba JFETs, that he says I can have, along with some other hardware, wire and whatnot.

Off the wall or not, I think you'll like it. The genuine class A single ended approach definitely has it's charms. Many of the OCD audio nuts feel it's the holy grail of amplification, and hey, you get to smell what they're stepping in first hand, and on the cheap thanks to the diy aspect.

One thing you may want to consider is upgrading from the cheapie SMPS that was part of the kits to a linear supply. Yes, this will push up the total cost a bit, but you don't want to hamstring the little bugger. For example, THIS would work perfectly for a stereo pair of amp camp amps, and ensure you were getting everything they have to offer.

 

[MrBoat]

Off the wall or not, I think you'll like it. The genuine class A single ended approach definitely has it's charms. Many of the OCD audio nuts feel it's the holy grail of amplification, and hey, you get to smell what they're stepping in first hand, and on the cheap thanks to the diy aspect.

One thing you may want to consider is upgrading from the cheapie SMPS that was part of the kits to a linear supply. Yes, this will push up the total cost a bit, but you don't want to hamstring the little bugger. For example, THIS would work perfectly for a stereo pair of amp camp amps, and ensure you were getting everything they have to offer.

Excellent. I must admit that I was not a fan of the bricks. This would be more my speed. Thank you for that suggestion.

 

[highfigh]

Nah. There's plenty of aluminum above ground to recycle. We have 55 gal drums of the stuff. Besides, most of the aluminum is coming out of Africa these days, anyway. I thought about welding up a heat sink out of some of the extrusions we use and some flat bar but I don't know if I feel like doing that unless I come up with something unique that I like. I liked the kit they had for it.

The good thing about parts like heat sinks that are off the shelf is that they sometimes come with specs for how much heat they lose and for a solid state amp, that's important.

The first stereo store I worked for was a big Pioneer dealer and at one point, they came out with a 30W ClassA amp- that thing sounded great and had serious balls.

 

[MrBoat]

The good thing about parts like heat sinks that are off the shelf is that they sometimes come with specs for how much heat they lose and for a solid state amp, that's important.

The first stereo store I worked for was a big Pioneer dealer and at one point, they came out with a 30W ClassA amp- that thing sounded great and had serious balls.

Yeah, I was reading about heat sinks last night and trying to find out specifics which is the problem with threads that can run so many pages on a topic. Also, there have been upgrades which were rather obscure. Went to order heat sinks and the shipping is as much as a heat sink is. Since this is a relatively new subject to me and I have not had time to think of alternative enclosure designs, I'm going to give it a few days. I also have some large heat sinks in older amps that have gone the way of the Dodo.

 

[highfigh]

Yeah, I was reading about heat sinks last night and trying to find out specifics which is the problem with threads that can run so many pages on a topic. Also, there have been upgrades which were rather obscure. Went to order heat sinks and the shipping is as much as a heat sink is. Since this is a relatively new subject to me and I have not had time to think of alternative enclosure designs, I'm going to give it a few days. I also have some large heat sinks in older amps that have gone the way of the Dodo.

The output transistors will generate heat, based on the bias current and how hard they're being driven- that info should be available from the manufacturer. The heat sink needs to allow it to cool, but still stay warm enough to be efficient. The next variable is the interface between the two and what is needed to couple them- this is where the hat sink compound enters the equation.

Here's a link to a supplier of heat sinks-

https://www.globalspec.com/industrial-directory/amplifier_heat_sinks

They should have info about sizing heat sinks, materials, etc.

 

[MrBoat]

A few things. After weighing building, vs. buying sinks, the novelty with the idea of building/machining them has subsided. I will just buy them. I weld/fab hundreds of things in a year. I have no adventures left in that trade by now after 30 years at it.

Sourcing all of the parts for this is an involved task. Ridiculous, considering the simplicity of this project. Mostly to do with hardware. Board spacers, screws, washers and jacks. It's just enough to where it almost justifies buying a bulk assortments instead of the near exact amount. Sadly enough, I just tossed all of my old desktop pc cases and parts. There is a load of M3 hardware in those. I'm at that age where I should have rounded up all of that stuff and put it in baby food jar racks like grandpas used to.

The information for this amp, and it's revisions, is seemingly allover the map. The PCB's in the picture at diyaudio, are likely somewhat outdated, at least optionally, as is the original parts list. The thread/s that address this are huge as was my google search trying to hash out specifics. I ended up having to pay extra shipping for 4 resistors that have been changed/added after the fact. Not a complaint as much as an observation. I do appreciate the free information, regardless of where it resides.

Still, I'm having fun at it and learning a bit as well. Have watched Nelson Pass "Burning Amp" videos and it's pretty nice of him to share this info with the DIY folks.

 

[highfigh]

A few things. After weighing building, vs. buying sinks, the novelty with the idea of building/machining them has subsided. I will just buy them. I weld/fab hundreds of things in a year. I have no adventures left in that trade by now after 30 years at it.

Sourcing all of the parts for this is an involved task. Ridiculous, considering the simplicity of this project. Mostly to do with hardware. Board spacers, screws, washers and jacks. It's just enough to where it almost justifies buying a bulk assortments instead of the near exact amount. Sadly enough, I just tossed all of my old desktop pc cases and parts. There is a load of M3 hardware in those. I'm at that age where I should have rounded up all of that stuff and put it in baby food jar racks like grandpas used to.

The information for this amp, and it's revisions, is seemingly allover the map. The PCB's in the picture at diyaudio, are likely somewhat outdated, at least optionally, as is the original parts list. The thread/s that address this are huge as was my google search trying to hash out specifics. I ended up having to pay extra shipping for 4 resistors that have been changed/added after the fact. Not a complaint as much as an observation. I do appreciate the free information, regardless of where it resides.

Still, I'm having fun at it and learning a bit as well. Have watched Nelson Pass "Burning Amp" videos and it's pretty nice of him to share this info with the DIY folks.

Do you make things to sell? How about teaching welding and fabrication? I watch welding videos frequently because I only took one class in high school (over 45 years ago and it was mainly oxy-acetylene & stick) and now, I want to make things that require welding but don't have the experience and skills to do it well. You would not be proud of my first welds- I guarantee it. They hold, but......

Have you ever repaired a boat prop? You could make a killing in that and all it would require is for you to do it the right way. Most of what I have seen was done relative quickly, but as soon as the blade hits something, it snaps off.

 

[MrBoat]

Do you make things to sell? How about teaching welding and fabrication? I watch welding videos frequently because I only took one class in high school (over 45 years ago and it was mainly oxy-acetylene & stick) and now, I want to make things that require welding but don't have the experience and skills to do it well. You would not be proud of my first welds- I guarantee it. They hold, but......

Have you ever repaired a boat prop? You could make a killing in that and all it would require is for you to do it the right way. Most of what I have seen was done relative quickly, but as soon as the blade hits something, it snaps off.

Yes, I make things to sell. Mostly high-end custom work. In our shop, over the last 18 years, I have designed, fab'd and welded about 99% of what has went out the door. Most of which has been for the marine industry. I also have an industrial scale welding rig installed at my home.

All of the welders in our shop are young men I taught from the beginning. They are all very good welders now. At least with our use of it. I went to school for it full time for 18 months initially. In all of my other trades, it was the missing, specialized ingredient. I ended up going to school over a clutch pedal I needed welded. Took me all day to find someone to fill in the linkage hole that had time to get to it. Took them 10 seconds to repair it. Metal fab was always a part of my other jobs, though.

Yes, I have repaired a boat prop but it takes specialized equipment to balance and set the pitch. We typically farm that out to experts that specialize in that. They can also do it cheaper than we can.

All of the young men I have taught to weld, including both of my sons, will tell you it is the toughest thing they have ever learned to do consistently well. And they have had what would be considered intense practice, all day, every day. My youngest son has managed to duke some 10-20 year hires we had briefly. Half of why they quit, or got run off, is because they could not take the fact that cubs were kicking their asses.

This is what I mostly built for the last 25 years was boat tops, towers and other furniture. Mostly anodized pipe and flat stock.

But, I also filled in between welding/repairing things such as these swivel fittings and such for the petro industry. These are for gasoline pipes that they fill the tankers with. I've also built fuel tanks and a bunch of other hardware for the racing industry, sewage treatment plants, you name it, I have likely welded it at least once.

For fun, here is a cart I tricked out for a customer.

 

[highfigh]

Yes, I make things to sell. Mostly high-end custom work. In our shop, over the last 18 years, I have designed, fab'd and welded about 99% of what has went out the door. Most of which has been for the marine industry. I also have an industrial scale welding rig installed at my home.

All of the welders in our shop are young men I taught from the beginning. They are all very good welders now. At least with our use of it. I went to school for it full time for 18 months initially. In all of my other trades, it was the missing, specialized ingredient. I ended up going to school over a clutch pedal I needed welded. Took me all day to find someone to fill in the linkage hole that had time to get to it. Took them 10 seconds to repair it. Metal fab was always a part of my other jobs, though.

Yes, I have repaired a boat prop but it takes specialized equipment to balance and set the pitch. We typically farm that out to experts that specialize in that. They can also do it cheaper than we can.

All of the young men I have taught to weld, including both of my sons, will tell you it is the toughest thing they have ever learned to do consistently well. And they have had what would be considered intense practice, all day, every day. My youngest son has managed to duke some 10-20 year hires we had briefly. Half of why they quit, or got run off, is because they could not take the fact that cubs were kicking their asses.

This is what I mostly built for the last 25 years was boat tops, towers and other furniture. Mostly anodized pipe and flat stock.

But, I also filled in between welding/repairing things such as these swivel fittings and such for the petro industry. These are for gasoline pipes that they fill the tankers with. I've also built fuel tanks and a bunch of other hardware for the racing industry, sewage treatment plants, you name it, I have likely welded it at least once.

For fun, here is a cart I tricked out for a customer.

I used to service boats and prep new boats for delivery- I saw some really good welds on the towers and racks, some weren't so great, so we returned those. I have been watching a lot of TIG welding videos- makes wire/flux core welding look like someone connected a coat hanger to a car battery with a set of jumper cables.

Is that cart used for golf/demo derbies? Really nice!

 

[MrBoat]

I used to service boats and prep new boats for delivery- I saw some really good welds on the towers and racks, some weren't so great, so we returned those. I have been watching a lot of TIG welding videos- makes wire/flux core welding look like someone connected a coat hanger to a car battery with a set of jumper cables.

Is that cart used for golf/demo derbies? Really nice!

Is actually made for a hunting camp. Then the owner decided it was too nice for that purpose and keeps it at his residence. Even though it's electric, it makes like 30+ mph and has multiple speed/power modes.

I've never had a weld rejected, even while in school. I would not take them to the instructor unless they looked like the book.

 

[highfigh]

Is actually made for a hunting camp. Then the owner decided it was too nice for that purpose and keeps it at his residence. Even though it's electric, it makes like 30+ mph and has multiple speed/power modes.

I've never had a weld rejected, even while in school. I would not take them to the instructor unless they looked like the book.

I made a mount for a vise that fits into the receiver of the hitch on my work van- looked great until I welded it. I can tack like a mother, but with as little experience as I have, I was forgetting to pull my welds, rather than push and I blew through in a few spots. Once I had ground and sanded the welds, I banged on it with a 2lb straight peen hammer to see if they would break, etched, primed and painted it with bed liner. Good enough for the first project.

In high school, one kid (not the smartest one) scratched his head when he was in one of the welding booths. Unfortunately for him, the torch was lit. Apparently, the poi he used on his hair kept the flame down.

 

[slipperybidness]

A few things. After weighing building, vs. buying sinks, the novelty with the idea of building/machining them has subsided. I will just buy them. I weld/fab hundreds of things in a year. I have no adventures left in that trade by now after 30 years at it.

Sourcing all of the parts for this is an involved task. Ridiculous, considering the simplicity of this project. Mostly to do with hardware. Board spacers, screws, washers and jacks. It's just enough to where it almost justifies buying a bulk assortments instead of the near exact amount. Sadly enough, I just tossed all of my old desktop pc cases and parts. There is a load of M3 hardware in those. I'm at that age where I should have rounded up all of that stuff and put it in baby food jar racks like grandpas used to.

The information for this amp, and it's revisions, is seemingly allover the map. The PCB's in the picture at diyaudio, are likely somewhat outdated, at least optionally, as is the original parts list. The thread/s that address this are huge as was my google search trying to hash out specifics. I ended up having to pay extra shipping for 4 resistors that have been changed/added after the fact. Not a complaint as much as an observation. I do appreciate the free information, regardless of where it resides.

Still, I'm having fun at it and learning a bit as well. Have watched Nelson Pass "Burning Amp" videos and it's pretty nice of him to share this info with the DIY folks.

Yeah, I always buy extra parts for any project, use them on the next project, and many vendors like Mouser and Parts-Express offer discounts for higher volume orders. Often, I could actually buy 10 resistors for the same price as 8, just as an example.

Nowadays, unless I am doing a very specific project, I likely have at least 75% of my parts and components already on-hand.

Even when friends are working on stuff, I tell them to come have a look at my stock before they place an order--I would rather see someone using a part rather than it sitting in my drawer "just in case I need it".

 

[MrBoat]

Yeah, I always buy extra parts for any project, use them on the next project, and many vendors like Mouser and Parts-Express offer discounts for higher volume orders. Often, I could actually buy 10 resistors for the same price as 8, just as an example.

Nowadays, unless I am doing a very specific project, I likely have at least 75% of my parts and components already on-hand.

Even when friends are working on stuff, I tell them to come have a look at my stock before they place an order--I would rather see someone using a part rather than it sitting in my drawer "just in case I need it".

I will have some leftovers from this project. And this likely won't be my last.