How about a collection of hacks and rules of thumb for audio.
It could be a simple chart showing you what range of volume your sealed speaker should use based on speaker size. You can do the complex math. And they just for fun see if the size you came up with matches the rule of thumb chart.
It could be a hack to help you pick the best transistor from a pile of possible transistors you could use for a project.
My guru says there is nothing as perfect every ear has its own preference. So why not pick a transistor my ear likes.
Let me get the ball rolling with my idea. (It could be a brain fart). So humor me.
The number one problem today with all parts is fake or substandard parts. Or picking the right part.
So I have this pile of transistors and we need to find the one type which will sound best.
Was looking at some videos on youtube where they explain how to build an amp with one transistor. A cap and a resistor.
What if I were to build a bread board where a single transistor is replaced one after the other. Power supply used is based on where in the amp the transistor is being used.
And I play some test tunes. or music and then swap out the transistors one by one. And just listen to the music. I could also use a spectrum analyser on my phone to get an idea of freq response off each transistor.
Do you think the idea has merit or do you have a better idea to quickly pick from a pile of similar transistors. The test rig could work with a single transistor or you could make one which works with PNP / NPN pairs. Im not chasing perfection just a quick and dirty test rig. Instead of a speaker we could use an audio jack and feed the signal to a scope or the mic in of your laptop. Also if its a fake it pops on the board. Worst case taking out a resistor or cap vs taking out a complete board and many other components with it.
Im still trying to understand how to pick the best transistor from a pile. With my component tester i.e. is HFE important as in higher HFE= Better. Or a certain pf value or its speed from the datasheet.
It could be a simple chart showing you what range of volume your sealed speaker should use based on speaker size. You can do the complex math. And they just for fun see if the size you came up with matches the rule of thumb chart.
It could be a hack to help you pick the best transistor from a pile of possible transistors you could use for a project.
My guru says there is nothing as perfect every ear has its own preference. So why not pick a transistor my ear likes.
Let me get the ball rolling with my idea. (It could be a brain fart). So humor me.
The number one problem today with all parts is fake or substandard parts. Or picking the right part.
So I have this pile of transistors and we need to find the one type which will sound best.
Was looking at some videos on youtube where they explain how to build an amp with one transistor. A cap and a resistor.
What if I were to build a bread board where a single transistor is replaced one after the other. Power supply used is based on where in the amp the transistor is being used.
And I play some test tunes. or music and then swap out the transistors one by one. And just listen to the music. I could also use a spectrum analyser on my phone to get an idea of freq response off each transistor.
Do you think the idea has merit or do you have a better idea to quickly pick from a pile of similar transistors. The test rig could work with a single transistor or you could make one which works with PNP / NPN pairs. Im not chasing perfection just a quick and dirty test rig. Instead of a speaker we could use an audio jack and feed the signal to a scope or the mic in of your laptop. Also if its a fake it pops on the board. Worst case taking out a resistor or cap vs taking out a complete board and many other components with it.
Im still trying to understand how to pick the best transistor from a pile. With my component tester i.e. is HFE important as in higher HFE= Better. Or a certain pf value or its speed from the datasheet.
The best hFE, the better, this is so. But also noise, frequency band width, SOA, mounting, availability for future restoring/ repair/upgrade, fakes, etc.
Personally I dislike BJT and prefeer voltage controlled devices: tubes (mainly compactron), JFET AND MOSFET, alone or inside an IC. Also dislike mixing technologies.
Personally I dislike BJT and prefeer voltage controlled devices: tubes (mainly compactron), JFET AND MOSFET, alone or inside an IC. Also dislike mixing technologies.
An underestimated but very important specification (BJT/J/MOS) is the transconductance.
With Jfet's groups of one specific model are A, B and C or R(ed), O(range), Y(ellow), G(reen), B(lue) and V(iolet).
The lowest grade (A / R) have the highest transconductance, which is preferred.
With BJT's, higher beta's come from smaller CB-barriers, and breakthrough is more appearent.
Designing with semi's is balancing the 'quality' of the components, the used topology for a given application, and the 'tonal experience'.
Besides that, it cannot be taken into control what is between the ears of a listener.
With Jfet's groups of one specific model are A, B and C or R(ed), O(range), Y(ellow), G(reen), B(lue) and V(iolet).
The lowest grade (A / R) have the highest transconductance, which is preferred.
With BJT's, higher beta's come from smaller CB-barriers, and breakthrough is more appearent.
Designing with semi's is balancing the 'quality' of the components, the used topology for a given application, and the 'tonal experience'.
Besides that, it cannot be taken into control what is between the ears of a listener.
Ok some progress. Instead of trying to build a one transistor amp to test. I found this Rockola Tone control board which uses one Transistor as a class A pre-amp. Im thinking this would make a good test bed for To92 package transistors.
It allows you to test with a wide range of voltages. Like this I guess we figure out various circuits that can test larger transistors.
We could split the transistor testing either on package size, voltage range or type.
Thank you for your insights. And rules of thumb.
I have also found that the lower the voltage the better the speed and the clarity i.e. not much gains to be had by using over specced parts.
It allows you to test with a wide range of voltages. Like this I guess we figure out various circuits that can test larger transistors.
We could split the transistor testing either on package size, voltage range or type.
Thank you for your insights. And rules of thumb.
I have also found that the lower the voltage the better the speed and the clarity i.e. not much gains to be had by using over specced parts.
I've never heard of the 'Rockola tone control (circuit drawing?), but all pre-amp stages are always class A.
How do you relate 'better speed' with clarity? Especially in tone control circuits, amplitude and phase are 'manipulated' out of the original balance into the preferred balance to obtain the subjective goal of the listener.
How do you relate 'better speed' with clarity? Especially in tone control circuits, amplitude and phase are 'manipulated' out of the original balance into the preferred balance to obtain the subjective goal of the listener.
Because your ear can not differentiate sound from one transistor to another unless it´s broken/shorted or oscillating, o biased so wrong that it clips half wave , something GROSS.
In the linear section, all sound the same.
Expecting differences in stage width, sweetness, low level definition, etc. is nonsense.
At most, a Germanium transistor (grossly obsolete and underperforming) can not reach 10kHz or some similar GROSS defect so it can be heard; but any competent transistor (99% of them) sounds the same.
No such thing.
Oh PLEASE!!! You mean THIS? [puke]
It simply does not work as you expect.
SPECIALLY if they are
On a broader view: Design is not made that way, although a noob might imagine it´s so.
Transistprs are SO MUCH THE SAME that Elektor Magazine , sick of reader´s questions (similar to yours) published a list of transistors , ANY ONE OF THEM would work perfectly well in most of the projects.
The famous TUPTUNDUGDUS list:
meaning
- Transistor Universal PNP
- Transistor Universal NPN
- Diode Universal Germanium
- Diode Universal Silicon
There were 3 such lists, not because of transistors (or diodes) being different, but because of Geographical and Availability reasons, there were European, "American" and Japanese lists.
In my view, they should have included "Russian" ones (Easter European included)
https://www.diyaudio.com/community/...entifying-this-transistor.346405/post-6002109
that´s just one European list, there´s more.
Thank you so my quest as to how to pick the best transistor from a pile continues.
I guess your right. My guru keeps telling me you have to build it and hear it.
My mind is you have to build it and test it on a scope since I dont trust my own ears.
A 3rd option Im starting to realize is to try it in a simulator first i.e. enter up your complete circuit in tina ti or Proteus and then chk.
But I really do not wish to re-invet the wheel cause for sure somebody must have done the ground work and made a list. To guide others.
I was going thru similar doubts with op-amps finally gave and just refered to guys who have done the grunt work and made lists as to which opamp works best for audio.
I guess your right. My guru keeps telling me you have to build it and hear it.
My mind is you have to build it and test it on a scope since I dont trust my own ears.
A 3rd option Im starting to realize is to try it in a simulator first i.e. enter up your complete circuit in tina ti or Proteus and then chk.
But I really do not wish to re-invet the wheel cause for sure somebody must have done the ground work and made a list. To guide others.
I was going thru similar doubts with op-amps finally gave and just refered to guys who have done the grunt work and made lists as to which opamp works best for audio.