Build a Phonograph Preamplifier - How Hard Can It Be?

[@ScottGrammer]

If your op-amp gets hot, you're doing something wrong.

[@cornwallonline]

Surely it sounded awful because of the lack of RIAA EQ? Also, your dual rail PSU diagram is in error....

[@robtitheridge9708]

yes it was please dont copy unless you know the corect way to wire diodes allso RIAA in playback cuts treble and boosts bass

[@CharlesHess]

For a guy who seemingly knows electronics you get pretty excited when your project works.

[@DIYerGuy]

To answer the question "How hard is it to build a solid-state pre-amplifier from scratch", the answer is it can be almost impossible if you don't know what you're doing. I'm an EE and there are so many issues with the example circuit that it's not worth going into, not to mention the error in marking the output polarity of the half-wave power supply (the output markings are reversed). I suspect the circuit and the video were a "teaser" of sorts, perhaps with errors thrown in(?) to be followed up at a later date with possibly more videos that ultimately results in a real practical FOE-NO pre-amp that has sufficient gain and follows the RIAA curve to within +/- 2dB. Otherwise, go out and buy a properly designed FOE-NO pre-amp. But hey, it was a fun video !

[@AstroSam66]

The polarity of the diodes in the rectifier schematics are wrong!

[@DIYerGuy]

It's not the diodes that are wrong... Note that the filter caps are properly connected for the polarity of the associated diodes. It's the marking on his schematic of + and - outputs on the paper that are reversed. The + marking (the output) is wrong.. It should be minus. Same for the minus output, it should indicate + .

[@AstroSam66]

@@DIYerGuy The diodes are in the wrong polarity. period. Just blah blah blah with the markings are wrong and other bs. They are wrong.

[@DIYerGuy]

Johannes, he is using an AC source and his power supply is basically what we call a half-wave rectifier because he's using one diode for each half of the AC wave: If you follow the circuit, on the positive half of the cycle, the TOP diode (in his diagram) will conduct and charge the top filter capacitor; Similarly, on the negative half cycle, the BOTTOM diode will conduct and charge the lower filter capacitor; Note that the filter caps are properly oriented for either the positive or negative part of the wave, that is, the + end of the filter cap is connected to receive the positive part of the wave and the - end of the bottom cap for the negative part of the wave. It's the markings on the output of the power supply that are incorrect, they are reversed.

[@petersage5157]

RIAA eq is quite simple and easy to implement in an op amp feedback circuit, especially in these days of internet machines. Just do the jazz hands routine on the gargler chanting "op amp riaa schematic" and the secrets will be revealed to you. That said, last I checked you could buy a mass manufactured preamp with RIAA equalization for about twenty quid. As for which EQ sounds best, that depends on which EQ was used on the recording, innit? The whole idea is that EQ out more-or-less exactly undoes EQ in.

[@MaxWattage]

This was utterly abysmal. You hired a Timmy Mallett tribute act to draw not just one, but two incorrect schematics, and then upload it to KZbin as a teaching video. I know these videos are targeted at young beginners, but that is all the more reason to hire an actual qualified engineer to ensure that what you are teaching is correct.

[@Ajinkya_Mahajan]

the dual polarity supply generation was awesome idea.

[@eDRoaCH]

Missed you!

[@CABohol]

Nice!

[@BehrouzKashkar]

the thing is preamps which run of ac transformer produces humm and noise if you could make something out of battery it would sound nicer, i hope some day someone teach us how to make preamp and amplifier out of tubes so we could have real analog experience

[@clemensmayer9171]

the Tube distortion pedal I made earlier on this channel is pretty much 3 overdriven preamps in series, if you experiment around with the component values you should be able to turn it into a tube preamp with clean output.

[@atschirner]

This is an analog amplifier.

[@E-learners97]

Hello brother, very great video teach electronic

[@MAYERMAKES]

finally a reason to keep all the AC/AC PSus in my bin on top of all the AC/Dc Psus! let the hoarding commence!

[@gerryroberts662]

I'm working a disk cutter that ran on tubes, i cannot seem to pick the correct schematic for this 1951 Phono. I jeep changeing my ideas fr the circuit, i have parts, but none that fit the schematics i google.i think google wants ppl to use BC457 transister or 2n222 Transister or 2n309Transister. i have 234 transisters, but not sure i can use them ??

[@saucebosspl]

That was so wrong. Nothing makes sense in this video. You have to attenuate high frequencies and boost bass. When I see phono preamp with 100k resistance in both signal path and feedback then I know the only thing it's gonna amplificate is noise. Phono preamp is very susceptible to interference and that half bridge, half assed power supply will destroy last bits of performance. Element 14 you can do so much better.

[@scottbaeder37]

welcome back to the doobl-eee-doo...

[@BehrouzKashkar]

finally!

[@Mr.Beauregarde]

01:04 all these little grooves, Provided "all these" equals 2 or fewer

[@smamas114]

So if a replace the rc4580 op amps with the newer OPA1656 will be a difference in sound quality ?? will worth spending the money for 10 pieces OPA1656 ?

[@slaweksuchy2702]

no

[@smamas114]

@@slaweksuchy2702 When i replaced the rc4550 with tl082 i have noticed a difference on my genius sw 5.1

[@slaweksuchy2702]

@@smamas114 impossible due to very poor schematic design

[@smamas114]

@@slaweksuchy2702 So what do you recommend for replacing? Audio system is Logitech z5500 ,i have both the z5500 and the z906,the 906 has the ne5532 and sounds clear than z5500

[@smamas114]

@@slaweksuchy2702 It’s all i want to hear,thanks 👍

[@PhoenixRevealed]

I see my comment regarding your pronunciation of "phono" got removed. Whatever.

[@DIYerGuy]

His peculiar pronunciation of that world also caught my attention and I was about to also make a comment on Fon-OH... vs Foe-NO... with the later being the correct pronunciation... But since your comment was removed I'll not provide mine. :)

[@jon4715]

cool video, i'd love to see some more in-depth electrical engineering hifi audio projects, though maybe outside of the scope of this channel. as for the phono stage...the whole amplification circuit is contained within the op-amp right? so just directing current and hooking up power? so essentially plugging in a source and connecting a power cable, right?

[@kennye6088]

It all could have been done using 4 or 6 transistors (2N3904, 2N4401, JAN2N2222a, and 12 volts DC. The JAN2N2222A and the 2N3904, are true low noise devices, ranging 4 to 6 dB Max.. Using 1% resistors and 10% polypro's and NPO's will give you a real low noise level of about 1.456 dB..., with a well filtered 12 volt supply.

[@qwertykeyboard5901]

1:16 Or a piezoelectric transducer!

[@TedSchoenling]

Never had to rectify an op amp... Build guitar pedals all the time

[@CharlesHess]

Phōnograph, monaural

[@danielkohwalter5481]

The schematic is wrong... The polarity on the "power supply" is wrong... There is no way to someone learn electronics with all those mistakes... and all AGAIN, because last video with a project (the 13.6V power supply) the circuit also was completly wrong!!! The circuit presented on that and on this video both never is going to work!!!

[@kylesmithiii6150]

Yes, this phono preamp circuit is wrong. For starters, the phono line-in should go to an RC circuit of some 10uF + 47k Ohms connected to the non-inverting input of the opamp. And the opamp negative feedback configured as an RIAA filter/decoder. There are plenty of schematics on the internet for the RIAA phono pre-amp.

[@tseckwr3783]

f'on oh?

[@chrispotts2010]

This video is a shambles from start to finish! Several mistakes, mostly caused by carelessness, but some due to lack of basic knowledge. I hope that nobody uses your ramblings as a learning aid because it isn't and you are potentially dangerous. How can Element 14 allow you to associate with them? I am disturbed by your lack of respect for your viewers.

[@hz1234]

I work in the field of electricity and I have a talent for quick learning and innovation. But I don't have an official certificate I'd like to get a degree in electricity☹️

[@kennye6088]

Since 1994, the NE5332, is not as good as it once was. China does a bad job in making them. In fact I have discovered that only JAN2N2222A/JAN2N2219A, and JAN2N2907A/JAN2N2905A are the only good BJT to use today. Their QA Control is still #1. Since records are not the thing today, no one cares about the QA any more. You can match BJT's, you can not match chips or IC's. The spec's are always on the high end for IC's. But they work.