Greetings DIYers. Yes, the title is exactly what I intend to build, as silly as it might seem.
I want to build a moderate power guitar amplifier using solid state actives. Why obsolete and salvage parts? Why solid state and not tubes?
There's a few reasons:
Here's what I have on hand so far:
1 120V:24V 40VA power transformer from a furnace
1 120V:16V 15VA doorbell transformer.
1 40W 10" speaker left over from a long-dead practice amp.
1 reverb tank, left over from the same long-dead amp.
A few hundred different transistors, in varying quantities
I am willing to buy some parts, if for no other reason than I know I'll have to. I'm going to need various resistors and capacitors for filters, voltage dividers, setting operating points for the transistors, etc. I'm even willing to buy a few complementary transistors, as I saw almost no complementary pairs in the parts drawers. I may have to purchase some voltage regulators as well, depending on what power supply circuits I am able to come up with. Beyond that however, I really would prefer to limit myself to the transistors on hand for the design, because that's the essence of this game: How good of a sound can I make with this old stuff, even if I have to force it into behavior it was never designed for?
Here's how I see this going. I welcome any input and discussion as the project moves along through these phases. If this order of design is wrongheaded, I also welcome input on what might work better.
That's all I have for now. I am still working on transcribing the photos of my hackerspace's parts drawers. I figured I'd get this initial post up so I could get input on the basic design outline and the intended design process/sequence. I will have parts lists in my next post. They will be long. I am tempted to put them into tables for easier readability.
I want to build a moderate power guitar amplifier using solid state actives. Why obsolete and salvage parts? Why solid state and not tubes?
There's a few reasons:
- I already have a few full power tube amps. They sound great at face-melting volumes, but their weight and volume levels make them slightly less practical for apartment practice or an impromptu jam or demo. A low-power tube amp would also fill this roll decently well, but still be heavy, and also be expensive. Post-COVID supply chain hangovers and the current war in Eastern Europe have constrained tube supply and made them even more expensive than they already were.
- I have access to bunch of obsolete and salvage parts through my own collection of stuff, and membership at a hackerspace. At least some of my BoM will be cheap or free this way.
- Being constrained by what I can get for extremely cheap or free will make this somewhat of a challenge and force me to get creative with the circuit design, and might even be fun.
- And finally, these older and salvaged parts are probably not going to run as clean and linear as modern parts would. I see that as a potentially useful quality in a guitar amplifier. Exactly how and why the poor electrical performance of old tube circuits creates the je ne sais quoi sought by guitarists has been discussed extensively, and IMO, still hasn't been fully worked out. But in either case, if bad electrical behavior can be pressed into a musically useful role, that bad behavior is possibly desirable to design for.
Here's what I have on hand so far:
1 120V:24V 40VA power transformer from a furnace
1 120V:16V 15VA doorbell transformer.
1 40W 10" speaker left over from a long-dead practice amp.
1 reverb tank, left over from the same long-dead amp.
A few hundred different transistors, in varying quantities
I am willing to buy some parts, if for no other reason than I know I'll have to. I'm going to need various resistors and capacitors for filters, voltage dividers, setting operating points for the transistors, etc. I'm even willing to buy a few complementary transistors, as I saw almost no complementary pairs in the parts drawers. I may have to purchase some voltage regulators as well, depending on what power supply circuits I am able to come up with. Beyond that however, I really would prefer to limit myself to the transistors on hand for the design, because that's the essence of this game: How good of a sound can I make with this old stuff, even if I have to force it into behavior it was never designed for?
Design Outline
Here's the outline of the design that's been forming in my head over the past week:- Class AB push-pull output section based on a complementary pair using some of the higher power transistors selected from my hackerspace's parts drawers, running at high voltage, into the primary of the doorbell transformer, stepping the voltage down and the current up to drive the speaker. Yes, I know this is unnecessary, appropriate BJTs or MOSFETs should be able to push enough current to drive the speaker directly. However, I believe the interactions between the output devices, transformer, and speaker are an important part of the vibe of the old circuits that have caught my ear. Thus, I think it is worth at least trying to design the output stage to use a transformer.
- A preamp section using a number of the small signal and not-so-high power transistors from the parts drawers, running at medium and lower voltages. Exactly how many gain stages, I'm not sure yet. I would like to span from nice clean tones, through edge-of-breakup, to a moderate crunch. Very high gain distortion is a maybe; we'll see what sounds I'm able to get out of the parts on hand.
- A power supply section running the furnace transformer, with a voltage doubler or quadrupler to get up to the voltages needed to make use of the doorbell transformer as an output transformer. Other portions of the power supply section can offer lower voltages appropriate for the transistors in the preamp section.
- Maybe use the reverb tank for a reverb circuit.
- All of this into a single combo chassis to keep the amp readily portable.
Timeline / Steps
Here's how I see this going. I welcome any input and discussion as the project moves along through these phases. If this order of design is wrongheaded, I also welcome input on what might work better.
Transistor Selection
I need to work out which transistors are going to appear in the output and preamp sections. This will determine the voltage and current requirements from the power supply. I am leaning towards using the few JFETs and MOSFETs in the pile. This is mainly because I understand those are more readily coerced into similar misbehavior as the high-mu triodes and power pentodes that came to define the voicing of many tube amp circuits. However if some of the BJTs, SCRs, UJTs, or other miscellaneous parts available in my hackerspace's parts drawers might also be useful, I am interested.
Power Supply Design
I need to design a power supply to meet voltage and current needs of the transistors selected for preamp and power amp roles in the previous phase. I don't have any super firm ideas here yet. I like the designs I've seen from Walt Jung, but I don't know if those can be realized at both the high voltage I want in the output section, and the obsolete parts I'm limiting myself to for this project. I suspect I may end up starting a separate thread in the Power Supply section of the forums for this bit if crossposting is not against the rules.
Power Amp Design
Next, I will need to come back to the Power amp and work out its design in greater detail than the current vague idea of "high-voltage push-pull complementary pair across a doorbell transformer, because lol". This is where I expect a lot of the discussion on exactly how and why tube circuits misbehave and which of those misbehaviors are musically useful and worth attempting to replicate.
Preamp Design
Moving on to the preamp section, I expect even more time will be spent on how to get the transistors in this section to misbehave in fun ways, and how that misbehavior can be leveraged towards producing the kinds of voicing and character I want out of the amp.
Testing and tweaking
There should be some testing and tweaking of each of the above bits as they get built, but I expect there's going to be a lot more once start I connecting them together. I should anticipate lots of time playing riffs into the amp, critical listening, staring at bizzare oscilloscope traces with a "WTF?" look on my face, and coming back here with my observations to get help with the Why and How behind those WTFs.
Build the cabinet/enclosure
Honestly, this one gets into woodworking and cabinetry, which feels out-of-scope for this forum. If I remember to take picutres, I'll be happy to share them, though.
That's all I have for now. I am still working on transcribing the photos of my hackerspace's parts drawers. I figured I'd get this initial post up so I could get input on the basic design outline and the intended design process/sequence. I will have parts lists in my next post. They will be long. I am tempted to put them into tables for easier readability.
I have finished transcribing the pictures of my hackerspace's electronics parts drawers. This is not the full set of components. I have deliberately omitted a good bulk of the collection for being 7400 and 4500 series logic chips -- which I don't see as likely to be useful unless I start getting into some multi-voice channel switching fanciness.
I have noticed that there's a very short edit window on posts. So I could post tables of the transistors on hand now, but they would be just tables of name/type/polarity, and nothing of their specs At 230+ devices that's a lot of device model numbers that are probably obscure, and you'd need to look up their specs to know if they're useful or not.
Would you guys like to see basic specs for each transistor type like max voltage, max current, max wattage, amplification factor, etc, or just a list of the devices on hand? The latter I can post right away. If I am to post the former, I will be spending several days hunting down datasheets for over 230 transistor types.
I have noticed that there's a very short edit window on posts. So I could post tables of the transistors on hand now, but they would be just tables of name/type/polarity, and nothing of their specs At 230+ devices that's a lot of device model numbers that are probably obscure, and you'd need to look up their specs to know if they're useful or not.
Would you guys like to see basic specs for each transistor type like max voltage, max current, max wattage, amplification factor, etc, or just a list of the devices on hand? The latter I can post right away. If I am to post the former, I will be spending several days hunting down datasheets for over 230 transistor types.
If you are limited to a 40 VA 24V transformer for power, you don’t need to get too picky when it comes to transistors. One pair similar to TIP41 and a dozen jelly bean TO-92s will give you all you’re going to get - about 12 watts. Preamp circuitry can be forced to work with just about anything - and I’m sure at least one or two out of 230 have reasonably low noise for the first two stages.
Sounds like an exciting project. There's a nice thread on design and build of a SS guitar amp by MJL...
My only recommendation would be to drop your idea of the doorbell transformer as an OPT. If I think of all the classic SS amps that made it in to the recording studio for hits, AFAIK none had an OPT, tone was coming from elaborate preamp stages.
My only recommendation would be to drop your idea of the doorbell transformer as an OPT. If I think of all the classic SS amps that made it in to the recording studio for hits, AFAIK none had an OPT, tone was coming from elaborate preamp stages.
What's your thought process on 12W output power? doing the math for efficiency of a Class AB stage (~78.5%) across 40VA tells me I can get up to about 30W of power (40 * .785 = 31.2, round down to account for additional inefficiencies and that the preamp will draw a tiny amount of power as well.) Are you thinking that after rectification and filtering, I'll have only about +/- 15V, any real circuit will only be able to swing about 90% of rail to rail?
Before you can get to your step 1: Transistor selection you need to make some decisions on what you want this amp to do. One of those is how much power output you want. Before you can figure out how to get there you need to know the impedance of the 10 inch 40 watt speaker. Given that, you need to figure out how much voltage you need to put across that speaker to reach the desired output power. Then remember that the doorbell transformer that you want to use as an OPT has a 7.5 to 1 voltage step down ratio.
Putting 40 watts into an 8 ohm speaker requires almost 18 volts RMS. That means that you will need to put 134 volts RMS across your 450 ohm doorbell transformer OPT to get the 17.8 volts across the speaker required to make 40 watts. That would be almost 380 volts peak to peak, requiring +/- 190 volt supplies. Can't get there from here with a 24 volt power transformer and most scrounged transistors.
Assuming that you have a 4 ohm speaker and 10 watts is enough, you will need 47.4 volts RMS, or almost 134 volts peak to peak. You are still looking at +/- 70 volt supplies to drive 10 watts into a 225 ohm OPT.
Putting 40 watts into an 8 ohm speaker requires almost 18 volts RMS. That means that you will need to put 134 volts RMS across your 450 ohm doorbell transformer OPT to get the 17.8 volts across the speaker required to make 40 watts. That would be almost 380 volts peak to peak, requiring +/- 190 volt supplies. Can't get there from here with a 24 volt power transformer and most scrounged transistors.
Assuming that you have a 4 ohm speaker and 10 watts is enough, you will need 47.4 volts RMS, or almost 134 volts peak to peak. You are still looking at +/- 70 volt supplies to drive 10 watts into a 225 ohm OPT.
Since you're in the US, land of plenty, I'd not randomly restrict yourself to the iron you have on hand. Many times I see (if you know where to look) old stereo receivers being sold quite cheap, which would net a much better power transformer for what you want to do. And for the thermal solution you'll need to have; a nice heat sink. Gotta mount the output devices to something, how about something already designed for ambient air cooling?
If you're set on an output transformer, one possibility would be to take what you have and make it an autotransformer. That would require dismantel and rebuild. I'm not about to quote winding turns, but it's basically a single winding with a tap for the speaker output. Magnetic flux still couples into the windings from the tap point on down, so it's a transformer. You'd join the ranks of McIntosh and...some of those early American car radios with the big Delco germanium output transistors.
If you're set on an output transformer, one possibility would be to take what you have and make it an autotransformer. That would require dismantel and rebuild. I'm not about to quote winding turns, but it's basically a single winding with a tap for the speaker output. Magnetic flux still couples into the windings from the tap point on down, so it's a transformer. You'd join the ranks of McIntosh and...some of those early American car radios with the big Delco germanium output transistors.
Just buy a few old amps / recievers from sellers, in for parts or working condition.
You will be surprised at what is on offer, and the price...
You can then mix and match the parts.
Alternately, build a 1875 with a Gainclone type circuit, save yourself the time and effort, less than $50 should do the trick, it is enough for most use, not for concerts.
Higher up the chain, 7294 and 1943 / 5200 should be enough.
There should be many threads here about guitar amps, and some discussion why tubes are better.
I suggest you read up, decide what is best, take stock of what you have in hand, and then proceed to build (or as I suggested) modify another amp.
The speaker in hand can also be checked out for performance.
Indeed, you might be able to obtain old guitar amps from the likes of Fender and Marshall, among others, price I cannot say.
You will be surprised at what is on offer, and the price...
You can then mix and match the parts.
Alternately, build a 1875 with a Gainclone type circuit, save yourself the time and effort, less than $50 should do the trick, it is enough for most use, not for concerts.
Higher up the chain, 7294 and 1943 / 5200 should be enough.
There should be many threads here about guitar amps, and some discussion why tubes are better.
I suggest you read up, decide what is best, take stock of what you have in hand, and then proceed to build (or as I suggested) modify another amp.
The speaker in hand can also be checked out for performance.
Indeed, you might be able to obtain old guitar amps from the likes of Fender and Marshall, among others, price I cannot say.
Last edited:
24V/40VA will be fine for a small output stage, the 16V can drive the pre amp stage.
Do not expect very high performance, the transformer is low powered.
Do not expect very high performance, the transformer is low powered.
I thought I'd posted the impedance in the OP, but I checked again and apparently I forgot. It's 8 Ohms.
Honestly, I think 20 Watts is the upper bound I'm willing to put across the speaker, given its rating of 40W. That's the common practice I've seen for amp power vs speaker power ratings: having the speakers rated for 2x or more the clean output power of the output stage. That makes sense, given that as the output stage is driven into clipping, power delivered into the load starts increasing rapidly, approaching 2x of the clean power as the clipped waveform approaches a square wave. I also don't want to exceed the voltage rating of the transformer so to avoid shorting it out with inductive flyback voltages if the output stage is ever driving into clipping, so 16Vrms is the upper bound. 16Vrms would give me 32W into an 8 Ohm load, but that's getting uncomfortably close to the speaker's 40W rating. So yeah, let's call 20W the upper bound of the target output power.
I was getting confused at your numbers, and was about to make a smartass remark about the existence of voltage doublers and accusing you of mixing up the conversion factors for RMS to Vpeak and RMS to Vpeak-to-peak, but I double checked, and you're right. For some reason, I was mixed up about the voltages one gets post rectification -- you get Vpeak, not Vpeak-to-peak after rectification. I would need some serious voltage multiplication to get up to the voltage levels needed to drive the speaker through the transformer given impedance and winding ratios.
I can appreciate why running high voltage and output transformers were abandoned once transistors started becoming more powerful. It does make things simpler.
So I suppose if I am to insist on using the doorbell transformer, I should be ready to content myself with somewhere between 5-20W total output. 20W is the pie in the sky goal, 5W is the "You Tried" consolation prize.
In the OP, I stated that I already have a few tube amps. I should also state I also presently have a little 4W solid state thingy. This kit looks nifty, but I still need to buy tubes, which would add another $50-100 dollars depending on my selection. Cost will only go up from there if I target the 20W I am targeting for this solid state build.
I have an all mosfet SE amp running on my bench that uses local feedback around each stage to get near perfect triode curves from a mosfet or pentode vacuum tube. It feeds a purpose built OPT designed for a 6C33 Soviet voltage regulator tube. It is a Toroidy TTG6C33CSE which is not within the realm of "cheap or free" but not bad at about $100 US including shipping when I got them. You can't tell that this is not a SET without looking at it, and when driven by my old ADA MP-1 guitar preamp is does sound a lot like a cranked Fender Champ fed by a germanium Fuzz Face or Tone Bender.
I see where the OPT is going with this, but there are some hurdles to overcome. I'm running about 300 volts of B+ into a pair of paralleled $10 mosfets to get about 40 watts of SE power. I'm burning over 100 watts of power in the huge heat sink needed to support a class A amp of this magnitude. This is clearly not in the scope of "portable practice amp." The power transformer needed to run two channels of this amp should arrive in the mail today. It weighs over 10 pounds.
I could also suggest a typical push pull "tube type" output circuit using mosfets instead of tubes into a toroidal low voltage power transformer being used as the OPT. Here you would need a transformer with a pair of 120 volt primaries wired in series. The secondary voltage would need to be in the 24 to 48 volt range to keep the B+ down to reasonable levels. Here you are a pulling each half of the primary to ground through a tube or mosfet on alternate half cycles, so you only need about half the total B+ voltage that you would need if simply matching the output of a conventional CS transistor stage to an 8 ohm speaker with a small transformer.
As you stated "setting the controls for the heart of the sun" and plugging in a monster overdrive box will send the output stages into clipping. The peak voltages in a guitar amp driving a guitar speaker at or near its resonant frequency can be far beyond the B+ voltage. I have seen spikes to about 2500 volts in an overdriven guitar amp that ran on a 430 volt B+ voltage. It's likely that the resonant frequency of a 10 inch guitar speaker lies within the guitar's frequency range too.
I see where the OPT is going with this, but there are some hurdles to overcome. I'm running about 300 volts of B+ into a pair of paralleled $10 mosfets to get about 40 watts of SE power. I'm burning over 100 watts of power in the huge heat sink needed to support a class A amp of this magnitude. This is clearly not in the scope of "portable practice amp." The power transformer needed to run two channels of this amp should arrive in the mail today. It weighs over 10 pounds.
I could also suggest a typical push pull "tube type" output circuit using mosfets instead of tubes into a toroidal low voltage power transformer being used as the OPT. Here you would need a transformer with a pair of 120 volt primaries wired in series. The secondary voltage would need to be in the 24 to 48 volt range to keep the B+ down to reasonable levels. Here you are a pulling each half of the primary to ground through a tube or mosfet on alternate half cycles, so you only need about half the total B+ voltage that you would need if simply matching the output of a conventional CS transistor stage to an 8 ohm speaker with a small transformer.
As you stated "setting the controls for the heart of the sun" and plugging in a monster overdrive box will send the output stages into clipping. The peak voltages in a guitar amp driving a guitar speaker at or near its resonant frequency can be far beyond the B+ voltage. I have seen spikes to about 2500 volts in an overdriven guitar amp that ran on a 430 volt B+ voltage. It's likely that the resonant frequency of a 10 inch guitar speaker lies within the guitar's frequency range too.
In the various discussions I have read, I get the impression that tube plates are relatively tolerant of the massive flyback voltage spikes, though you do have to watch out for the transformer insulation handling the voltage to hand. Is my intuition correct that with mosfets or BJTs, the flyback voltages could set the magic smoke free, and that I'd want to select something with a Vdsmax well in excess of the +/- voltage of the power rails if I have such an option available to me?
I've seen this output stage on many a diagram of a tube amp circuit. As I understand, in a push pull setup, B+ is fed to a center tap of the primary. As I understand, if I wanted to duplicate this topology, I would need this doorbell transformer to have a center tap, with N-channels on either side. This doorbell transformer, as far as I can tell when probing with my multimeter, does not have a center tap on its primary. So, as I understand, I'd need to do a more conventional Common Source topology with the sources of a complementary pair on one end of the OPT, and the other end of the OPT grounded, and thus need the full +/- rails for whatever power level I am targeting.
I'll see if there's anything else in the parts bin that may lend itself to such a topology. Alternatively, there's another member at the hackerspace who's made some large Tesla coils, so I know he has magnet wire appropriate to both high voltage and high current -- I'll see what he's willing to share. It may be possible to wind my own OPT appropriate for the circuits I can realize with the transistors on hand.
While I and many another musician would agree with you, I only agree to an extent. I contend that it is not just the tubes themselves which give the distortion character we have come to know and love, but the electrical misbehavior of tubes, as that misbehavior interacts with the rest of the circuit, that gives the creamy distortion characteristic attributed to tubes. It is further my contention that transistor-based circuits can be designed in such a way that they electrically misbehave in a similar way as tube-based circuits, and can produce a similarly pleasing distortion characteristic, even if the circuit needs to be more relatively more complex to do so. The reason most solid-state circuits have not, is IMO, because most solid state circuits have been designed to run as clean as possible for as cheap as possible. And even even when SS circuits were designed for distortion, again, it was done as cheaply as possibly, or not all of the misbehavior of tube circuits was chased after because the circuit would get extra complex. Of course you're not going to get the same distortion characteristic from a single opamp and anti-parallel set of small signal diodes as you would from the distortion being spread across 3 or more common-cathode triode stages, a DC-coupled cathode follower, a differential triode pair, and a set of pentodes running push-pull through a transformer with minimal negative feedback.
I genuinely believe a circuit with the goodness ascribed to tubes can be had from transistors, even if I have to design a circuit that'd make a young EE fresh from college scream in horror and beg me to stop Doing It Wrong. I'd not have started this thread otherwise.
Okay, totaling up the transistor counts, there's a total of 227.
I also have 13 SCRs, 1 Triac, and 3 UJTs (today I learned that Unipolar transistors existed). Are these potentially useful as amplification, tone shaping, or power supply elements?
I will start with the FETs, since I'm not yet deep enough into hyper-nerd mode to go digging through 209 datasheets for a transistor type I'm not yet sure I'm going to use.
What properties would you like to see for them? So far I have:
Anything else you'd want to see to compare between the different FETs?
- 29 Germanium bipolar (mostly PNP),
- 180 silicon bipolar (mostly NPN, with some Darlington pairs thrown in for good measure)
- 5 JFETs (looks like complementary pairs from a family)
- 13 MOSFETs (all but 1 are N-channel)
- 120 miscellaneous other components (that I'm not wholly sure why I transcribed)
I also have 13 SCRs, 1 Triac, and 3 UJTs (today I learned that Unipolar transistors existed). Are these potentially useful as amplification, tone shaping, or power supply elements?
I will start with the FETs, since I'm not yet deep enough into hyper-nerd mode to go digging through 209 datasheets for a transistor type I'm not yet sure I'm going to use.
What properties would you like to see for them? So far I have:
| Name | Type | Polarity | Mode | Vds Max | Vgs Max | Vgs on | Vgs off | Rds On | Ig Max | disspation | package |
|---|
Anything else you'd want to see to compare between the different FETs?
You won't use the SCR's and TRIAC's, and most probably also not the UJT's.
Please build up a list of the transistor types and quantities you have. I guess some of us might know some of them and their significant properties. And get rid of that doorbell-to-output transformer idea, unless you're willing to dismantle and rewind it.
Best regards!
Please build up a list of the transistor types and quantities you have. I guess some of us might know some of them and their significant properties. And get rid of that doorbell-to-output transformer idea, unless you're willing to dismantle and rewind it.
Best regards!
That's a good idea as such, but you are going to wind up your own OPT then. Wich would be a cool project in itself. You would have to purchase some winding wire though.
Okay, here are the lists of the different transistors. I don't have counts, I'll get those later. I'll pull datasheets for electrical properties later. Tables are behind spoiler tags to attempt to respect your vertical screen space.
Most of the descriptions came from the sickers parts drawers, not me looking up datasheets, so they might be wrong.
Most of the descriptions came from the sickers parts drawers, not me looking up datasheets, so they might be wrong.
Bipolar
Germanium
| Name | Polarity |
|---|---|
| 2N513 | PNP |
| 2N539 | PNP |
| 2N540 | PNP |
| 2N575 | PNP |
| 2N43A | PNP |
| 2N174 | PNP |
| 2N777 | PNP |
| 2N778 | PNP |
| 2N326 | NPN |
| 2N369 | PNP |
| 2N376 | PNP |
| 2N378 | PNP |
| 2N388 | NPN |
| 2N441 | PNP |
| 2N462 | PNP |
| 2N1012 | NPN |
| 2N1396 | PNP |
| 2N1412 | PNP |
| 2N1412A | PNP |
| 2N1556 | PNP |
| 2N1754 | PNP |
| 2N1760 | PNP |
| 2N2082 | PNP |
| 2N2138 | PNP |
Silicon
| Name | Polarity |
|---|---|
| 2N1613 | NPN |
| 2N1711 | NPN |
| 2N1564 | NPN |
| 2N930 | NPN |
| 2N327 | PNP |
| 2N333 | NPN |
| 2N339 | NPN |
| 2N340 | NPN |
| 2N706 | NPN |
| 2N730 | NPN |
| 2N2151 | NPN |
| 2N2193 | NPN |
| 2N2197 | NPN |
| 2N2218 | NPN |
| 2N2219 | NPN |
| 2N2221 | NPN |
| 2N2222 | NPN |
| 2N2369 | NPN |
| 2N2405 | NPN |
| 2N2904A | PNP |
| 2N2905 | PNP |
| 2N2906A | PNP |
| 2N2907A | PNP |
| 2N2946A | PNP |
| 2N3016 | NPN |
| 2N3019 | NPN |
| 2N3053 | NPN |
| 2N3054 | NPN |
| 2N3117 | NPN |
| 2N3209 | PNP |
| 2N3250 | PNP |
| 2N2351 | PNP |
| 2N3300 | NPN |
| 2N3301 | NPN |
| 2N3302 | NPN |
| 2N3468 | PNP |
| 2N3567 | NPN |
| 2N3569 | NPN |
| 2N3585 | NPN |
| 2N3632 | NPN |
| 2N3642 | NPN |
| 2N3643 | NPN |
| 2N3646 | NPN |
| 2N3715 | NPN |
| 2N3724 | NPN |
| 2N3725 | NPN |
| 2N3740 | PNP |
| 2N3767 | NPN |
| 2N3772 | NPN |
| 2N3790 | PNP |
| 2N3902 | NPN |
| 2N3903 | NPN |
| 2N3905 | PNP |
| 2N3906 | PNP |
| 2N3947 | NPN |
| 2N3962 | PNP |
| 2N3964 | PNP |
| 2N4001 | NPN |
| 2N4013 | NPN |
| 2N4035 | PNP |
| 2N4036 | PNP |
| 2N4037 | PNP |
| 2N4062 | PNP |
| 2N4209 | PNP |
| 2N4234 | PNP |
| 2N4237 | NPN |
| 2N4238 | NPN |
| 2N4356 | PNP |
| 2N4398 | PNP |
| 2N4399 | PNP |
| 2N4405 | PNP |
| 2n4900 | PNP |
| 2N4901 | PNP |
| 2N4910 | NPN |
| 2N4914 | NPN |
| 2N4916 | PNP |
| 2N4918 | PNP |
| 2n4921 | NPN |
| 2N4922 | PNP |
| 2N4923 | NPN |
| 2N4957 | PNP |
| 2N5086 | PNP |
| 2N5087 | PNP |
| 2N5089 | PNP |
| 2N5137 | NPN |
| 2N5301A | NPN |
| 2N5032 | NPN |
| 2N5306 | NPN |
| 2N5038 | NPN |
| 2N5320 | NPN |
| 2N5321 | NPN |
| 2N5322 | PNP |
| 2N5323 | PNP |
| 2N5334 | NPN |
| 2N5415 | PNP |
| 2N5416 | PNP |
| 2N5447 | PNP |
| 2N5449 | NPN |
| 2N5629 | NPN |
| 2N5680 | PNP |
| 2N5681 | NPN |
| 2N5682 | NPN |
| 2N5880 | PNP |
| 2N5882 | NPN |
| 2N5883 | PNP |
| 2N5885 | NPN |
| 2N5886 | NPN |
| 2N5986 | PNP |
| 2N6051 | PNP |
| 2N6052 | PNP |
| 2N6053 | PNP |
| 2N6058 | NPN |
| 2N6059 | NPN |
| 2N6107 | PNP |
| 2N6109 | PNP |
| 2N6121 | NPN |
| 2N6213 | PNP |
| 2N6261 | NPN |
| 2N6282 | NPN |
| 2N2685 | PNP |
| 2N6287 | PNP |
| 2N6290 | NPN |
| 2N6295 | NPN |
| 2N6299 | PNP |
| 2N6316 | NPN |
| 2N6385 | NPN |
| BD327 | NPN |
| BU507 | NPN |
| D41D2 | PNP |
| D41D5 | PNP |
| D42C2 | NPN |
| D44C5 | PNP |
| D44H2 | NPN |
| D45C5 | PNP |
| D45H2 | PNP |
| D45H5 | PNP |
| MJ10003 | NPN Darlington |
| MJ10004 | NPN Darlington |
| MJ10007 | NPN Darlington |
| MJ10008 | NPN Darlington |
| MJ10009 | NPN Darlington |
| MJ10022 | NPN Darlington |
| MJ10023 | NPN Darlington |
| MJ11011 | NPN Darlington |
| MJ11012 | NPN Darlington |
| MJ11017 | PNP Darlington |
| MJ11018 | PNP Darlington |
| MJ11028 | PNP Darlington |
| MJE105 | PNP |
| MJE180 | NPN |
| MJE200 | NPN |
| MJE210 | PNP |
| MJE253 | PNP |
| MJE340 | NPN |
| MJE371 | PNP |
| MJ410 | NPN Darlington |
| MJ490 | PNP Darlington |
| MJ4033 | NPN Darlington |
| MJE3055 | NPN |
| MJE13002 | NPN |
| MPS918 | NPN |
| MPS3563 | NPN |
| MPS3704 | NPN |
| MPS4355 | PNP |
| MPS6507 | NPN |
| MPS6512 | NPN |
| MPS6514 | NPN |
| MPS6516 | PNP |
| MPS6518 | PNP |
| MPS6523 | PNP |
| MPS6531 | NPN |
| MPS8098 | NPN |
| MPS8099 | NPN |
| MPSA13 | NPN Darlington |
| MPSA42 | NPN |
| MPSA43 | NPN |
| MPSU01 | NPN |
| MPSU02 | NPN |
| SPS2336 | NPN |
| TIP121 | PNP |
| TP2N45 | NPN |
FETs
JFETs
| Name | Polarity |
|---|---|
| 2N4856 | N-channel |
| 2N4858 | N-Channel |
| 2N5114 | P-channel |
| 2N5115 | P-channel |
| 2N5462 | P-Channel |
MOSFETs
| Name | Polarity |
|---|---|
| BUZ11 | N-Channel |
| BUZ54A | N-Channel |
| IRCZ24 | N-Channel |
| IRF250 | N-channel |
| IRF130 | N-channel |
| IRF234 | N-channel |
| IRF123 | N-channl |
| MPF6661 | N-channel TMOS |
| MTH50N05 | N-channel TMOS |
| MTP10N25 | N-channel TMOS |
| MTP25N05 | N-channel TMOS |
| MTP25N10 | N-channel (TMOS?) |
| MTP30P06 | P-channel TMOS |
Miscellaneous
| Name | Description |
|---|---|
| LH0070H | Precision 10V reference |
| CMP01 | Fast Precision Comparator |
| ADC0804 | 8-bit ADC |
| BA10393 | Dual Comparator |
| ADC1001 | 10-bit ADC |
| LM108 | Precision Opamp |
| H11A5 | Optocoupler |
| DGM111 | Dual Driver w/ MOSFET switch |
| DS1221 | Non-volitile memory controller |
| 1232CP | Don't know |
| LM139 | Quad wide supply range comparator |
| MC1349 | Video IF Amplifier |
| MC1403U | Precision 2.5V reference |
| MC1404U | Precision 5v reference |
| MC1408L6 | 6-bit DAC |
| MC1048L8 | 8-bit DAC |
| MC1411 | Darlington Transistor Array |
| MC1413 | Darlington Transistor Array |
| MC1414 | Dual differential Comparator |
| MC1437 | Matched Dual OpAmp |
| MC1456G | Internally compensated opamp |
| mc1488 | quad EIA-232D line driver |
| MC14051 | 8:1 analog (de)mux |
| MC14066 | Quad Analog switch |
| MC14490 | Hex Contact bounce eliminator |
| MC144404 | PCM Codec-filter mono-circuit |
| WD1772 | Floppy drive controller |
| FD1791 | floppy drive controller |
| MAX180 | 8-channel 12-bit data acuisition system |
| MAX186 | 8-channel serial 12-bit ADC |
| i80186 | Yes, Intel did make a 186 between the 8086 and 80286 |
| i80188 | And an 8-bit bus little brother, just like the 8088 |
| DG189 | Analog Switch Mux w/ jfet switch |
| i80196 | Intel MCS-96 microcontroller |
| DG191 | high speed driver w/ jfet switch |
| ULN2001 | Darlington Transistor array |
| DG201 | CMOS QUAD SPST Analog switch |
| LM201 | opamp w/ external compensation |
| ULN2014A | High voltage, hi current darlington array |
| CA20033 | 100Mhz high power buffer amp |
| V20 | ?? |
| HCTL2016 | Quatdrature decoder/counter |
| LM205H | Positive voltage regulator |
| MM2012 | 1024x1 SRAM |
| DG211 | Quad SPST analog switch |
| MCP23017 | 16-bit i2c i/o expander |
| Max232 | dual channel RS-232 line driver/receiver |
| UDN2580 | Octal source driver |
| UDN2595 | 8-channel saturated sink driver |
| UDN2596 | 8-channel saturated sink driver |
| 26LS32 | Quad diferential line receiver |
| ULN2083 | 8 Darlington transistor array |
| ULN2814 | High voltage, high current darlington array |
| UDN2916 | Dual full bridge motor driver |
| LM2941 | 1A Adustable low dropout voltage regulator |
| PS2501-4 | 4-channel 5kVrms optoisolator |
| MIC29302 | 3A fast response low dropout voltage regulator |
| UDN2987A | 8 channel source driver w/ overcurrent protection |
| LM307 | Opamp |
| LM308 | opamp |
| CA3081 | High current common-collector NPN array |
| LM311N | comparator |
| LM311H | comparator |
| LM318J | opmap |
| LM318N | opamp |
| LM319 | dual comparator |
| MAX3223 | 3-5.5V dual RS-232 transceiver w/ Auto Shutdown |
| LM304T5 | 5v Linear Regulator |
| LM358 | dual opamp |
| LM393 | Dual differntial comparator |
| LM3940 | 1A 5V->3.3V LDO regulator |
| LF398 | sample and hold |
| LM431 | Adjustable precision zenner shunt regulator |
| TL441 | logarithmic amplifier |
| MAX485 | Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| SP488ES | Quad RS-485/RS-422 line receiver |
| LTC488 | Quad RS-485 line receiver |
| LTC491 | RS-422/RS-485 Driver/receiver pair |
| SP491GS | Full Duplex RS-485 Transceiver |
| TL494 | PWM control circuit |
| TL496 | 9V Power supply controller |
| TL497 | Switching voltage regulator |
| TL500 | Analog processor |
| TL505 | 10-bit ADC |
| DG508 | 8:1 mid-voltage mux |
| TL514 | Dual differential comparator |
| NE521 | high speed dual diff comparator |
| NE527 | voltage comparator |
| NE529N | voltage cmparator |
| NE529H | voltage comparator |
| NE530 | LED driver |
| NE532 | low power dual opamp |
| NE531 | high slew rate opamp |
| NE555T | timer |
| NE555N | timer |
| NE558 | quad timer |
| NE566 | Function generator |
| LM567 | tone decoder |
| NE570 | compander |
| NE571 | compander |
| TLC5940 | 16-chanel LED driver w/ PWM |
| UCN5804B | stepper motor driver |
| TL601 | PMOS analog switch |
| 6306-IJ | ??? |
| MAX680 | 5V->+/-10V converter |
| LM710H | voltage comparator |
| LM711 | dual differential comparator |
| LM733 | diferential amplifier |
| UA741 | general purpose opamp |
| LM747 | dual general purpose opamp |
| SN75179 | differential driver/reciever pair |
| MX7548KN | 12-bit DAC |
| LM568 | FM stero multiplex decoder /pll |
| UA772 dual opamp | |
| DM7838 | Tri-state Bus transciever |
| LM8200 | H-bridge |
| TL820 | Dual differential comparator |
| DAC8412 | 12-bit DAC |
| M12J45 | Bidirectional Triode thyristor (WTF isthat?) |
| MAC15A6 | Triac |
| MC4064 | Undervolt Sense |
Well, that's impressive. But I'm missing the quantities. With just one pc. per item they're almost useless for your intentions.
Best regards!
Best regards!
I managed to pick up a couple more transformers digging through the parts bins at my hackerspace.
120/208/240:24
120/208/240:19.2 Center tapped.
I was originally thinking voltage doublers to get the peak-to-peak voltage swing I need to make the power target, but I suppose wiring 120:24 transformers back to back isn't the worst power supply idea ever.
I also picked up few different massive chokes that came out of an old solar inverter. Inductance ranges from mid 500s to low 900s of mH, but the DC resistance on them are tiny -- all sub 0.1 Ohms. I'd need to get a set of 4-wire probes for the multimeter to measure. Don't know if those would be useful for filtering in the power supply or not.
Also, both of them look like they're made using alternating E-I laminations, as opposed to welding two stacks of E and I laminations together at the seam. So in theory, the transformers I picked up tonight can be re-wound. No small task, but that option is on the table, depending on how hardcore I decide I want to be.
Quantities varied from drawer to drawer. Some of bigger transistors were only 2 or 3 in a drawer, some of the smaller ones had few dozen. Do you have a short list of candidates? Or do you want counts of all 350+ transistors and other devices listed above?
Personally, I'm tempted to declare the FETs to be my candidate short list for the gain stages and power amp ouput stages, and leave the many BJTs be except for a few tasks like driving a reverb tank, FX loop buffer, power supply regulation, etc. the reasoning behind this is I understand FETs are more easily wired up to make them electrically misbehave in a manner similar to old vacuum triodes, which I think would be useful in voicing the amplifier.
120/208/240:24
120/208/240:19.2 Center tapped.
I was originally thinking voltage doublers to get the peak-to-peak voltage swing I need to make the power target, but I suppose wiring 120:24 transformers back to back isn't the worst power supply idea ever.
I also picked up few different massive chokes that came out of an old solar inverter. Inductance ranges from mid 500s to low 900s of mH, but the DC resistance on them are tiny -- all sub 0.1 Ohms. I'd need to get a set of 4-wire probes for the multimeter to measure. Don't know if those would be useful for filtering in the power supply or not.
Also, both of them look like they're made using alternating E-I laminations, as opposed to welding two stacks of E and I laminations together at the seam. So in theory, the transformers I picked up tonight can be re-wound. No small task, but that option is on the table, depending on how hardcore I decide I want to be.
Quantities varied from drawer to drawer. Some of bigger transistors were only 2 or 3 in a drawer, some of the smaller ones had few dozen. Do you have a short list of candidates? Or do you want counts of all 350+ transistors and other devices listed above?
Personally, I'm tempted to declare the FETs to be my candidate short list for the gain stages and power amp ouput stages, and leave the many BJTs be except for a few tasks like driving a reverb tank, FX loop buffer, power supply regulation, etc. the reasoning behind this is I understand FETs are more easily wired up to make them electrically misbehave in a manner similar to old vacuum triodes, which I think would be useful in voicing the amplifier.