So I've poked around a bit, and maybe my search-fu is weak, but I think this is a new(ish) question.
I'm just starting to dig into designing and building a simple guitar amp -- tubes, of course, which is why I'm here -- and have been pondering the basic building blocks.
See, I've got an Onkyo TX-SR706 that I really liked until its HDMI daughterboard fritzed. Seems like they used caps with too low operating temps. The suggested fix is to replace all the 100 and 220 caps with higher temp versions. That's a couple dozen tightly spaced SMD caps that I'd rather not mess with. Now, when I'm looking at this problem with the cover off the receiver, I see a lovely Onkyo HCPS (High Current Power Supply) sitting right there that seems to be just begging to be put to good use. Side note: there's a guy on ebay who claims to do the daughterboard fix for $75.
I've had trouble finding any sort of schematic for said power supply, too.
My question is: before I dive down a rabbit hole trying to figure out if I might be able to make it work in a guitar amp, is there anybody out there who can speak to whether this is either (1) a really bad idea or (2) a really good idea?
I'm just starting to dig into designing and building a simple guitar amp -- tubes, of course, which is why I'm here -- and have been pondering the basic building blocks.
See, I've got an Onkyo TX-SR706 that I really liked until its HDMI daughterboard fritzed. Seems like they used caps with too low operating temps. The suggested fix is to replace all the 100 and 220 caps with higher temp versions. That's a couple dozen tightly spaced SMD caps that I'd rather not mess with. Now, when I'm looking at this problem with the cover off the receiver, I see a lovely Onkyo HCPS (High Current Power Supply) sitting right there that seems to be just begging to be put to good use. Side note: there's a guy on ebay who claims to do the daughterboard fix for $75.
I've had trouble finding any sort of schematic for said power supply, too.
My question is: before I dive down a rabbit hole trying to figure out if I might be able to make it work in a guitar amp, is there anybody out there who can speak to whether this is either (1) a really bad idea or (2) a really good idea?
Yes, #1. Usually these power supplies didn't have high enough voltages for tube amps in general. Tubes operate on higher voltage, low currents where SS is opposite in general. Without knowing specifically what the power supply is, when you said "high current power supply", that's a huge clue. Not saying it can't be done, just too complicated,unless you know how to construct voltage doublers. It's better just to get the proper tranny.
Thanks.
That was my gut instinct, but I wanted to be sure. I'm sure I could sort out how to get voltage doublers going but I'd rather keep the whole mess simpler. It will be my first amp and I don't want to make it needlessly complicated.
A tube amp needs several hundred volts for B+, your Onkyo doesn't have that. Your tube amp needs 6.3vAC for the heaters, and the Onkyo doesn't have that. Unless you go cathode bias, you will need a negative supply for the power tube bias. You could probably find that in the Onkyo, but why use that whole big power supply for a couple milliamps of negative voltage, since you'd have to come up with all the other supplies anyway.
So I also vote option #1.
So I also vote option #1.
And ..... WHY "tube amp, of course" ???????????????????????????????
FWIW 10 to 100 SS amps are actually sold for each single Tube amp.
Maybe that means something 😉
FWIW 10 to 100 SS amps are actually sold for each single Tube amp.
Maybe that means something 😉
Simplest answer? I'm new here and posted this question in the wrong forum (tubes and valves). A moderator moved it here where it obviously belongs.
In a more complete context I have been playing around with electronics since getting my first proper electric guitar, and my interests have simply drawn me to doing a tube amp from the ground up. They appear to be simple circuits that can be forced to fail (in a pure signal processing sense) in interesting and musical ways. That and, well, tubes are cool. There's a cloud of electrons floating around that are absolutely integral to the sound. How is that not all sorts of awesome?
If I can cobble something together that sounds even a little bit good I'll make it a cabinet, etc etc -- it's a hobby. Besides, this is DIY Audio, and I'm doing it 🙂
It certainly does mean something. On a very important level it means that SS are much better suited to automated mass production and the economies of scale that provides. It's also a byproduct of the ability to consistently produce the same product. Once you've got a good circuit you can really make use of it. These can be really great things.
I have no interest in making a zillion of the same thing. For a good SS, I'd buy rather than build. I have a fun modeling combo (Peavey Vypyr VIP-3).
Of course, I will admit I haven't given SS even the first thought in all this.
Ok, if Tube is your favorite flavour, go with it.
Simply forget about the Onkyo transformer which is absolutely unsuitable.
Please check the AX84 guys: great people, had the bright idea of concentrating on a basic design and testing all variations which can be built around that platform, designing many killer amps in the process.
Check them, start with the most basic one, but build it in a larger chassis, because soon you'll be upgrading it.
Do not be tempted to start with the complex ones,the basic ones are already very good, and provide lots of "forced to fail (in a pure signal processing sense) in interesting and musical ways."
It makes it easier to get the difficult/expensive parts (transformers and chassis) because they either find suitable suppliers or even organize group buys.
Simply forget about the Onkyo transformer which is absolutely unsuitable.
Please check the AX84 guys: great people, had the bright idea of concentrating on a basic design and testing all variations which can be built around that platform, designing many killer amps in the process.
Check them, start with the most basic one, but build it in a larger chassis, because soon you'll be upgrading it.
Do not be tempted to start with the complex ones,the basic ones are already very good, and provide lots of "forced to fail (in a pure signal processing sense) in interesting and musical ways."
It makes it easier to get the difficult/expensive parts (transformers and chassis) because they either find suitable suppliers or even organize group buys.
Forgotten long ago at this point. I didn't really expect it to be useful -- I was just hoping.
I have and that does look interesting. That is definitely a direction I will be investigating eventually.
I'm actually thinking of getting my feet wet with one of the designs from the hundred buck challenge. This 6AF11 layout caught my eye:
Before you lose all hope of your HCPS transformer working you might want to check out the idea of using space charge tubes (Space Charge and Other Low-Voltage Tubes).
They were originally designed for use in car stereo systems where all that was available was a low voltage battery...after they got tired of dealing with noisy vibrators. I've been wanting to get around to building a space charge guitar amp for a while...whenever i get the time. I want to try to use an old laptop power supply or some other SMPS capable of sourcing a decent amount of current. It wouldn't be very powerful, but it would be fun to design and build.
They were originally designed for use in car stereo systems where all that was available was a low voltage battery...after they got tired of dealing with noisy vibrators. I've been wanting to get around to building a space charge guitar amp for a while...whenever i get the time. I want to try to use an old laptop power supply or some other SMPS capable of sourcing a decent amount of current. It wouldn't be very powerful, but it would be fun to design and build.
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