Vacuum Tube RIAA Phono Preamp Design

[@josepheccles9341]

I used 2 6U10 tubes in a desktop speaker stereo tube amp. I used section 2 for the phase converter. I used a 6J6 tube as the pre-amp tube. I found some 70.7 volt multi-tap transformers to use as output transformers. I found equal inductance taps to set it up in push pull output. It makes around 425 milliwatts clean. and it is really cute. For the high voltage, I used an inverter board from ebay. For filament supply I used a buck converter. The amp is supplied from a 12 volt power supply like they sell to power LED strips. Looks like a laptop charger.

[@CIRCUITDESIGNER]

Would like to see. Do you have a video?

[@josepheccles9341]

@@CIRCUITDESIGNER I don't make videos. I currently have it apart to better select some components. I was very new at this when I built it. I had chosen cathode resistors. I got the pre-Amp section good but was overloading the powers supply with the final stage. When I have it all done, likely it will only make about a watt and a half per channel.

[@soldermaster4737]

Please post the complete schematic and PCB layout for this 6U10 phono preamp as well as your power supply for this phono preamp.

[@holyvanguard]

I support this. I'd love to build one.

[@VinylRescue]

Cool project. I want to build my own tube phono preamp soon. I have two Pickering XV-15/625E carts that I use on my Technics SL-Q2 and Pioneer PL-7. I bought the LP Gear Vivid Line Contact (similar to the Micro Line) stylus replacements and they sound GREAT!

[@CIRCUITDESIGNER]

Saw your channel, I like the recovery idea. I recovered a couple video concerts. The original masters are gone forever. Channel is called "LostVideoRecovery" which has Gordon Lightfoot and the Dooby Brothers from 1970's Soundstage. Lots of work to recover.

[@dm.2023]

Best tube preamp video yet!

[@CIRCUITDESIGNER]

Thanks Dave, It took a long time to design and build.

[@skullheadwater9839]

I like that you are using compactrons, we need to continue to utilize the remaining NOS tubes to do our bidding. I experiment myself but usually on guitar amps.

[@SkunkieDesignsElectronics]

Very interesting idea :)

[@chazlabreck]

AS a tech for nearly 50 years i commend your creative use of the 6010 tube this way..I would love to build this little phono amp as im in need of one..unless you have the PC board for sale.

[@CIRCUITDESIGNER]

I only built two prototypes. I'm keeping one, the other is posted on Ebay. I have been thinking about ordering more boards however, building the preamp is very time consuming.

[@chazlabreck]

​@@CIRCUITDESIGNER yeah no doubt its a lot to build and your price on Ebay is very reasonable for all you put into it ..unfortunately i cant justify the money at this time.. really great work though . If you ever do sell the pc board i would be interested .. cheers.

[@holyvanguard]

Would you be interested in selling the schematic or even better the board diagram (not sure if that's the correct name) so I could order boards for personal use. I'm not an engineer but I can follow instructions and solder.

[@verderandy9161]

Gr8 job. Turned out beautifully. Thnx for sharing, Randy/GA

[@Torpengpogi]

how can i order from you a complete finish one including the power supply? thanks.

[@ericksonengineering7011]

Nice project and video, thanks! Love the triple triode. I think the opamp might not be needed. The output stage, a cathode follower, has a low (

[@CIRCUITDESIGNER]

I did jump out the op amp for some testing and found the RIAA curve shifted somewhat when I applied a 10K load so I stayed with the op amp as an impedance buffer. Thanks

[@oakmountainman7872]

Wow! Really enjoyed this! Would like to get two of these boards to build my brother a preamp he needs.

[@rickg8015]

Reminds me of the active RIAA design by Tim De Paravicini (Luxkit, E.A.R.), in some ways.. Looks sweet and sounds sweet.

[@CIRCUITDESIGNER]

Thanks, The 6U10 is a fun tube to design with.

[@AN-hz1fo]

Hi, thanks for sharing, very interesting choice of triple triode and great clear explanations, definitely high quality engineering! Would be very interested in your point of view of choosing active RIAA correction ? Thans

[@TheJimmydan67]

awesome sound quality very well done

[@harveyellis6758]

Nice project! Well done.

[@bledlbledlbledl]

a TRIPLE-triode ... i'd never heard of those before. looks good, sounds good. my only worry there is: does that enclosure have any ventilation?

[@CIRCUITDESIGNER]

Heat is no problem. Tube sections run at very low plate and filament current.

[@cobar5342]

Great work

[@CIRCUITDESIGNER]

Thanks for the comment. I still have the 2nd proto on Ebay. Probably not going to build any more, too many hours involved.

[@frankgeeraerts6243]

Turner has an interesting blog ( Australia )..............nice riaa amplifier, sounds good !

[@FilipeReishandmade]

I'd love to build one. Do youy plan to sell the PCB's ??

[@adrianoamorimribeiro9436]

Very very Good job! my friend . I want to build my own tube phono preamp

[@alanstich]

Gracias maestro

[@ceylonmooney]

u ever put your spare up for sale?

[@CIRCUITDESIGNER]

Yea I did on Ebay but no interest.

[@ceylonmooney]

why do that? i was askin 11 months ago. heck, you coulda told me.

[@KinoMoya]

Good Job! MM or MC?

[@CIRCUITDESIGNER]

Its currently set up for MM. I don't have a MC type to experiment with at this time. Thanks

[@ceylonmooney]

man this is cool. i would so luv to hear this in my system. audiophiles generally have a strong aversion to opamps. i dont know enough to understand. do you have a link for the ones ur gonna sell?

[@CIRCUITDESIGNER]

Op Amps are a good match for connecting to modern audio equipment. They make good impedance buffers. I only built 2 of these. May put the 2nd one on Ebay.

[@ceylonmooney]

@@CIRCUITDESIGNER well, plz lemme know if u do. or...is there a way to directly message thru youtube?

[@ceylonmooney]

@@CIRCUITDESIGNER if so, could u drop me a line? id sure like to know ahead of time.

[@ceylonmooney]

@@CIRCUITDESIGNER u put that 2nd phono amp up for sale yet?

[@litoboy5]

Cool

[@ceylonmooney]

hey im still interested drop me a line on AK

[@CIRCUITDESIGNER]

Hi, It's still on Ebay, Item ID: 155571675404

[@ceylonmooney]

@@CIRCUITDESIGNER nothing came up

[@malachi8446]

𝚙𝚛𝚘𝚖𝚘𝚜𝚖

[@Steven-pv1xr]

I have used tje 6U10 compactron as a phono preamp but i did not destroy good tube phonics with an op amp. If ypu know you are driving a tube section of 250k input impedance then you have no worries to drive direct from your triode

[@Steven-pv1xr]

Dont destroy ypur good tube audio by inserting an op amp. Your triodes can drive a preamp quite well. No nerd for op amp. You have destroyed all the good you have done