If the fundamental is at 200Hz, the 2nd harmonic is at 400Hz, not 300Hz. 400Hz is the 2nd, not the 3rd.
The 3rd would be 600Hz.
Jan
I'm not sure that 01a/201a is a good choice for "distortion generator".
It's "too" linear, even at horrible underload (like Vinylsavor made) in the harmonic structure the second is the dominating (if you choose appropriate operating point).
IMO choose another tube for this task.
If you have tube with good condition, the distortion even unnoticeable.
Sample -measured few years ago- (breadboard measuring: 1V in, CCS loaded 201a, 20R filament bias resistor, R.C.4 0.25A regulator, SiC CF output ):
So design the guitar not to generate harmonics and then use tubes to generate even harmonics.
The other way would be to use Digital Signal Processor (DSP) to process the guitar output strip out any odd harmonics and add in even harmonics.
DSP may not look as nice as glowing tubes, I liked the look of EL34's glowing Red, Orange, Purple, Blue.
If I get a chance I will post the schematic of a tube preamp designed for harmonic distortion and post the LTspice simulation. I'm watching Wimbledon Ladies Final at the moment 😂
What notes do a bass guitar produce, l mean the fundamental notes frequency?
The other way would be to use Digital Signal Processor (DSP) to process the guitar output strip out any odd harmonics and add in even harmonics.
DSP may not look as nice as glowing tubes, I liked the look of EL34's glowing Red, Orange, Purple, Blue.
If I get a chance I will post the schematic of a tube preamp designed for harmonic distortion and post the LTspice simulation. I'm watching Wimbledon Ladies Final at the moment 😂
What notes do a bass guitar produce, l mean the fundamental notes frequency?
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You also have to wonder what a starved filament would do to the unique harmonic distortion characteristics of this tube.
Ah yes, that I don't know how to simulate in LTspice, I don't have any characteristics linking filament voltage with other specifications. For certain it would increase distortion but no idea what it would do to harmonics, maybe someone has done some tests?
About decade ago Ale Moglia tried it.
"Ladies and gentlemen!
This is the tutorial, how to sc..w up an excellent tube, with totally wrong settings" 😈
"Ladies and gentlemen!
This is the tutorial, how to sc..w up an excellent tube, with totally wrong settings" 😈
D1 and D2 establish a Grid DC bias of about -1.2V
B+ HT voltage needs to be low and is 48 Volts
Distortion depends a lot on input voltage
-
The datasheet says use (on the filament) the minium filament voltage to make it work (in its application) , and not over 5V.
From my understanding, the filament/tube was designed for battery operation, where the operating voltages changed over time.
I do appreciate how diyers can make this tube operate in exceeding linear fashion, however my intention is to explore the tubes unique harmonic distortion characteristics.
I found this post about heater voltage (and the other posts in the thread) Changing Heater Voltage
Changing Heater voltage don't think its a big deal, too high and tube breaks, too low and maximum Anode current will drop off.
But not going to do much for distortion. The UX201A is a nice looking tube/valve.
Changing Heater voltage don't think its a big deal, too high and tube breaks, too low and maximum Anode current will drop off.
But not going to do much for distortion. The UX201A is a nice looking tube/valve.
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Where did you get the idea that this tube has unique distortion characteristics? The Thomas Mayer article (and his other info on this tube) is all about perfect sound?
He says "The purpose of the device is to present the sound of the tube itself in it's purest form with as little coloration as possible by other components in the signal path."
It could be too some people, perfect sound has harmonic content.
"Hi Xxx
the purpose of the circuit is to subject the signal to the unique distortion characteristics of this tube to alter the sound. The gain depends on the output transformer used. With the one I chose it has two output taps. One without gain and one with about 6dB gain
Best regards
Thomas"
"Hi Xxx
the purpose of the circuit is to subject the signal to the unique distortion characteristics of this tube to alter the sound. The gain depends on the output transformer used. With the one I chose it has two output taps. One without gain and one with about 6dB gain
Best regards
Thomas"
Too low filament voltage does more damage than too high. When using a regulator set it to nominal voltage. That is measured at the tube's pins, not at the point where the hook up wire attaches to the socket.
For odd harmonics, I would use a pentode as a pre-amp tube. For more distortion, a remote-cutoff pentode i.a EF83. 6.3V filament, no antics.
Hi Tnz
I have an Ale design 01a Pre with a little bit of "sand" in it.
I am in West Auckland, so if you are anywhere in the vicinity, you are welcome to have a taste, or play with an 01a circuit, PM me.
I too looked longingly at the Mayer version, but baulked at the weight of iron required.
Nice to hear about a stash of 01a's in NZ.
Cheers
Gn
I have an Ale design 01a Pre with a little bit of "sand" in it.
I am in West Auckland, so if you are anywhere in the vicinity, you are welcome to have a taste, or play with an 01a circuit, PM me.
I too looked longingly at the Mayer version, but baulked at the weight of iron required.
Nice to hear about a stash of 01a's in NZ.
Cheers
Gn
Hey Gn!
A westie! 😉
I'm in Murray's Bay.
Your preamp looks 😍😍😍..i bet it would sound amazing!
I'll send you a pm👍
A westie! 😉
I'm in Murray's Bay.
Your preamp looks 😍😍😍..i bet it would sound amazing!
I'll send you a pm👍
You are correct C1 does not have much purpose, the two diodes D1 and D2 give about a negative Grid of -1.2 Volts. C1 removes any noise that the diodes make. But it could be any value probably 1uF would be better.
Yes indeed distortion can be appealing to many, ironically I spent many years trying to remove distortion not build it in lol.
Good luck with your 01A adventures!
Hi Rich,
Today I auditioned my 01A tube. B+113.5 VDC ( loaded with a 20H 120ma Gardners choke) . Grid -8V "battery baised " , linear regulated filament @ DC 4.7V
OMG!! the tone is SO thick. And the bass is not too saggy/floppy. It still has air and pace, with tonal character for decades!
This tube is a KILLER