It is fun to see how little goes into some of these amps.
Thanks for taking your tops of for me. drool
Thanks for taking your tops of for me. drool
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Amp Guts Photos - Official Thread - Lets see those pics
- Thread starter svtb15
- Start date
That last one is a power amp only, it seems, therefore, its greater simplicity.
The PC board looks like a hand-drafted home made board. Is that an upgrade from a turret board or something?
I think that they’re going for 70’s old school. The type of PCB’s that were done back then.
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1972 Gibson Super Thor 65 Watts RMS @ 4 ohms. A thing of great beauty.
That would have been pretty familiar for amps made in the day, and even up through the 80s. I worked in a very small computer related shop during college, and our boards were laid out on transparent film with two colors -- red for one side, blue for the other, and black for pads. The boards were made by photo-resist etching, so they used red and blue light for the two sides during exposure.
And even into the 90s and possibly through the present, the really cheapest electronics still use single sided phenolic boards with through-hole parts that can be assembled by hand in fly-by-night sweatshops. Take apart something really cheap, like an alarm clock, and you might be astonished.
But even today, there's nothing particularly wrong with that layout per se if your circuit isn't complex enough to need two sides. Modern boards bring some other benefits: Plated holes, better adhesives, and solder mask, all contribute to a more rugged and repairable board. And those fancy features have gotten cheap enough that there's no reason not to use them. On an old single sided board, you had to be extremely careful desoldering those components to avoid lifting the pads off the board.
This is a current production Neve preamp clone subassembly. The hand laid out printed circuit boards from the 70's are replicated to be as authentic as possible.
- Feb 12, 2006
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- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
I may use CAD PCB manufacturing software (CAM) but I do all my layout placements and routing manually using the same general ideas that I used 35+ years ago when tape-ups and "red & blues" were the norm. The reason for this is that I can control how the currents in the circuits flow and especially how they flow into the ground system. This goes back to laying out designs for consoles, where small noise problems multiply quickly into large problems. I learned a whole lot studying console layouts, necessary when servicing large frame and medium frame consoles. Each designer had their own unique fingerprint.
Mr. Foxen
Commercial User
I do the same; in fact, I've never used the auto-route function. I too came from drafting manually, so it was a logical move to keep on with the same method of layout. Sometimes I have to revise a few times if I paint myself into a corner, but it doesn't happen very often.
- Feb 12, 2006
- 61,062
- 5
- 221,099
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
Auto-route for audio is abysmal unless you define the rules so strict that you may as well route it manually anyway.
I don't design commercial electronics for my day job, since we have a whole team of electrical engineers, and I'm just a physicist.
Over the years I've definitely seen a difference between engineers who came up through the old school, versus younger workers who are quite talented but learned on CAD and SPICE from day one. A few of the designers get a reputation for being good with analog, and the analog work goes to their desks. None of them use auto-route. The good news is that analog tends to be an order of magnitude simpler than digital in terms of component size and count, so manual routing is rarely costly.It must be so much harder for something like a console, where you've got analog running among multiple subsystems. In my designs (typically they exist only through proof-of-concept), an analog signal chain rarely travels more than an inch or two before getting swallowed up by an ADC. And the newer digital stuff has gotten so clean that it can coexist with analog. I use ExpressPCB because it's so easy, and nothing I make ever gets out into the wild. My designs tend to be "a physics experiment that happens to be laid out on a circuit board."
Beautyfull work! Your experience in large console is a big plus here, as it is for the HPF too.
I have issues with autoroute as well. I like to see what it can do and get maybe five different layouts, choose one, then massage it with manual routing. Automation is not there yet.
It isn’t unusual for me to go into the output data file which is in ascii, bypassing the interface, and fine tune the coordinates. This allows me to get them set exactly where I want them.
As for consoles, combining digital and analog is very complicated. On the plus side, a lot of console design assemblies are repeated. They can be shared amongst different products.
Integrating sub assemblies from different suppliers is a large undertaking. Examples of sub systems include displays/touch screens, networking, faders, computer systems, power supplies, and automation. The console has to be interfaced to many systems. Then the computer manufacturer updates the OS, both new features but in some cases taking away or restricting features that were relied on. Sometimes it takes lobbying from the industry to get them to relent or come up with an acceptable workaround. That takes time. Relyi g on external entities only complicates things. It’s a major undertaking and explains why multiple teams working together are required.
It isn’t unusual for me to go into the output data file which is in ascii, bypassing the interface, and fine tune the coordinates. This allows me to get them set exactly where I want them.
As for consoles, combining digital and analog is very complicated. On the plus side, a lot of console design assemblies are repeated. They can be shared amongst different products.
Integrating sub assemblies from different suppliers is a large undertaking. Examples of sub systems include displays/touch screens, networking, faders, computer systems, power supplies, and automation. The console has to be interfaced to many systems. Then the computer manufacturer updates the OS, both new features but in some cases taking away or restricting features that were relied on. Sometimes it takes lobbying from the industry to get them to relent or come up with an acceptable workaround. That takes time. Relyi g on external entities only complicates things. It’s a major undertaking and explains why multiple teams working together are required.
Sounds just like you're describing a band.
That is one of the things I loved about the photography I did. Beyond purchasing supplies (film, chemicals, paper, etc.) no one, nothing one got in the way of my art.
Except perhaps the weather, sometimes. 
But, I did have workarounds depending on the situation.
