OREAD
The idea for a simple equalizer preamp came up in the EQ OREAD thread because of the apparent similarities to the 1980 Elektor SUPRA design proposal. Although they are not at all similar, BJTs were also connected in parallel in the OREAD template. Basically, the parallel connection was viewed critically by some users - and not entirely without good reason.
The idea was born to create a new SUPRA that was only intended for use with MM systems. Please read the OREAD thread, where you will also find the NETWORK that can be used.
Happy DIY,
HBt.
The idea for a simple equalizer preamp came up in the EQ OREAD thread because of the apparent similarities to the 1980 Elektor SUPRA design proposal. Although they are not at all similar, BJTs were also connected in parallel in the OREAD template. Basically, the parallel connection was viewed critically by some users - and not entirely without good reason.
The idea was born to create a new SUPRA that was only intended for use with MM systems. Please read the OREAD thread, where you will also find the NETWORK that can be used.
Happy DIY,
HBt.
The experienced and resourceful self-builder knows exactly which BJTs are suitable for this circuit. Perhaps you will feel called upon to make a suitable suggestion.
My general answer for "this (as you have so aptly stated) interesting but useless suggestion" is:
BC550, BC560, 2SK170 & 2SJ74 ... a variety of other LF transistors can also be used without remorse, 2SCxxxx or 2SAxxx ... etc.
No hard feelings!
Dear Nico,
please send me a PM, so that we can professionally work out the ... in the background. I am interested in your expertise.
Please do not hesitate to contact me,
HBt.
please send me a PM, so that we can professionally work out the ... in the background. I am interested in your expertise.
Please do not hesitate to contact me,
HBt.
The history of its creation in pictures ...
The RIAA network is placed either between "feedback & core-output" or between "feedback & buffer-output" - two options that will each generate a completely different sound character.
The RIAA network is placed either between "feedback & core-output" or between "feedback & buffer-output" - two options that will each generate a completely different sound character.
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We also see the well-known RIAA network in the Aladdin - MM Wonder EQ.
20nF -> (10nF FKP || 10nF FKP)
6.6nF -> (3.3nF FKP || 3.3nF FKP)
Supra2024 belongs in a shielding tinplate housing!
Happy DIY,
HBt.
20nF -> (10nF FKP || 10nF FKP)
6.6nF -> (3.3nF FKP || 3.3nF FKP)
Supra2024 belongs in a shielding tinplate housing!
Happy DIY,
HBt.
There are many options for the power supply, from battery power to @catd's fantastic overkill power supply board, or this one:
PSU option
it's all fine.
PSU option
it's all fine.
Dedicated employee wanted!
The only thing missing for the breath of life is a PCB,
Who will take the risk?
HBt.
The only thing missing for the breath of life is a PCB,
Who will take the risk?
HBt.
I recognize a diamond buffer, these seem to be coming back into great fashion at the moment. But yes, of course the buffer can be designed as a diamond.
However,
if you can find the two jFet's in your own stock, I prefer the Fet's. And also the dimensioning of the components that I suggested.
However,
if you can find the two jFet's in your own stock, I prefer the Fet's. And also the dimensioning of the components that I suggested.
But,
a really good diamond as a buffer is of course very interesting, especially with the famos BJTs TTC004B & TTA004B, instead of the well-known BD139/140.
a really good diamond as a buffer is of course very interesting, especially with the famos BJTs TTC004B & TTA004B, instead of the well-known BD139/140.
Take this as a stupid question. In complementary output stages I'm used to see two diodes between the bases of the PNP and NPN device to get their operation point right and avoid "zero crossing" distortion. Am I completely on the wrong track? Is it maybe different with power amplifiers?
Everything observed correctly, there is no real difference to the power amplifier. A diamond is a little bit different.
What about a Ruby or Emarald. Do they observe correctly or also different😴?
Oh, an interjection from Nico, supported by Kay.
I suggest that we reserve the gems for the hunters of lost youth ..!
If you two squires can contribute something constructive to the project, please do so- otherwise, feel free to intervene from time to time.
😉
No hard feelings,
HBt.
I suggest that we reserve the gems for the hunters of lost youth ..!
If you two squires can contribute something constructive to the project, please do so- otherwise, feel free to intervene from time to time.
😉
No hard feelings,
HBt.