Tube vs solid state phono pre-amp shootout!

[@Gabster1]

Thank you for another great video and putting a lot of effort and time and showing us how to upgrade those preamps

[@kdntool9369]

I have one of the EAR834 kits on the way due to arrive any day now. I have a chassis, transformer, and the upgraded signal path cap’s waiting patiently for it to get here. Just need to order the silver mica caps for the RIAA section. Thank you for your content, it is a pleasure to watch and learn.

[@SkunkieDesignsElectronics]

Very cool!

[@justins.4839]

This was perfect timing! Just bought a t11 open box off ebay. This series was extremelyyy helpful to understand how and why to change the caps. Appreciate the time and effort put into this!!

[@SkunkieDesignsElectronics]

Glad I could help!

[@andyfarmer2661]

Thank you so much for this series of videos. Great job! You got me off my ass and I now have a great sounding tube phono stage in the modified T11. The EAR834 clone board remains collecting dust. Too many decisions on how to proceed. One box or two, Lenco Heaven/Thorsten Loesch mods or not, upgrade the regulation in the power supply or stay with whatever the clone board provides? Someday. All of your mods greatly improved this little budget amp. I did add some extra mods which I think might be of interest to anyone trying this. Easiest of all is a set of Russian 6N2P-EV tubes. The Chinese 6N2 tubes that came with my Little Bear T11 weren’t noisy but didn’t sound that great. The EH 7025 tubes sounded richer and generally better, but the 6N2P-EV were even better yet and quite inexpensive. They especially helped enhance the detail. Your results may vary but at this price it’s worth a try. There was some hum so I wrapped the power switch wires with copper tape but didn’t ground that wrapping so I don't know but perhaps that helped. I also substituted a Hammond 154E 20H choke for the 1.5 K resistor in the power supply. It has about the same resistance, so all the voltages stayed the same. It is also tiny so fit right onto the PC board. Hum is greatly reduced, but the exact way the wires get stuffed into the case when you put the lid on has enough effect that maybe I just did that better on the final assembly. Maybe it was the choke, maybe the copper tape. I cannot say for sure. Finally, I upgraded the RIAA caps as per your video. Much better, but it still sounded somehow a little off. The bass was a little flabby and the highs lacked detail as compared to my existing Schitt Mani 1. A simple tube amp should equal or exceed detail of a transistor amp like this. One of the forums suggested that Little Bear may have botched the RIAA correction. As is the case with internet boards there was some back and forth as to how best to implement an RIAA correction, but folks seemed to settle in on a solution by T. Layton which employed 250pf, 300Kohm and 900pf, 3.6Mohm. (Link: www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=67059&start=408). This really seemed to clean things up although I didn’t use anything other than my ears to confirm. I suppose a Spice model followed by a frequency sweep with a reverse RIAA network attached would be best, but it sounds good, so I am leaving it be. You are so good with test equipment perhaps you will show us how in some future phono project. I will admit that I find RIAA correction to be a little intimidating and was happy to take T Layton’s solution without testing or tweaking. I know that Allen Wright believed the calcs and Spice models were not enough and that every phono stage needed final tweaking to adjust the resistors. He apparently would inject a square wave and tweak the resistors until he got the proper wave form out. I love your videos and am particularly enjoying your KT120 project. Great stuff. I know you got some grief on that R300 project but don't let them get you down and please keep up the good stuff you are doing here. You are the best.

[@ChuckNorrisUltra]

Thanks for this comment!

[@5thlevelweb887]

Stephe have you thought about tube gain stages for DIY multibit DACs? It seems the circuit would be similar to a tube phono pre-amp, minus the RIAA Eq and perhaps with input transformers.

[@acghifiaudio-vinyland78rpm53]

Thank you for this shootout. Hum is not fun, as we tubeheads say :) Luckily there are plenty of remedies. A signal to noise of -60 db should be in reach, and usually enough for Hifi but for studio gear values down to -85 to -90 are possible but require more tinkering around with the stuff.

[@henni1964]

Great video series on modding the T11. I learned a lot about soldering on these boards, thank you so much. Changing also the tiny ceramic caps for some mil. spec. silver mica and Siemens styroflex improved the overall sound to the next level. Using the toroidal transformer from the T10 (fits only in an external casing) and some 6N2P tubes from the fifties, I am quite happy with the sound.🙂

[@SkunkieDesignsElectronics]

Glad to help

[@insurrectionindustries1706]

I know phono stages are particularly difficult due to the very low level signals and the difficulty in keeping noise out of such low level signals, I’m very impressed that these can be relatively quiet. I know that isn’t easy.

[@Nihil1st1347]

Now I seem to get it. The hybrid preamp with MM phono stage I had, just didn't bring it, accompanied by my Rega P3 and Goldring 1006 cartridge, all good intentions set aside. Though that preamp I owned was an eyecatcher for sure.

[@cobar5342]

Thank you for this review. Some nice outcomes here

[@SkunkieDesignsElectronics]

Glad you like them!

[@VinylRescue]

I was going to ask in which direction the Mica caps go, but after a quick Google, I found they are non-polar so it doesn't matter which way they go in. 🤔🤔😜😜

[@SkunkieDesignsElectronics]

And I updated the BOM, sorry for being dramatic, I just loath them so much lol.

[@VinylRescue]

@@SkunkieDesignsElectronics I didn't think you were being dramatic. It does make you wonder how many other people may have bought the wrong quantity 😂?! As long as we can laugh about it later then we're doing good!

[@VinylRescue]

I just found another minor tweak that I'm doing to it now along with waiting on a new ground post. The small ground wire on the PCB is cheap metal wiring, not copper! I'm replacing it with 18 gauge copper wire to attach to a new 1877Phono GNDPOST Grounding Post from Part Connexion so I can use a banana plug on my ground wire from my turntable. I really don't like the spring-loaded push-in ground post that it comes with.

[@rickg8015]

Great work, Stephe.. For lower cost coupling caps, I find the Obbligato Ultra Caps smooth and grain free..

[@SkunkieDesignsElectronics]

Thanks for sharing!

[@rickg8015]

@@SkunkieDesignsElectronics Hi Stephe.. I watched the vid again with a larger screen last night, the caps you put in look more like precision Axial Polystyrene.. Which are also really good..

[@SkunkieDesignsElectronics]

The caps I used in the feedback circuit are some NOS mica caps I had on hand from another project.

[@andrewm1894]

Really looking forward to next gen phone preamp. I want to build this

[@SkunkieDesignsElectronics]

Soon!

[@adrianovicente1895]

C3g-RIAA-Vorverstaerker von Hans-Peter Völpel Qual sua opinião sobre este preamplifier ???

[@SkunkieDesignsElectronics]

No idea, never seen one.

[@marcusbrown1767]

One more question. My tonearm has a flat spade. What's the answer about that? Also is there a cover I could use to completely cover the top and hide the tubes? Thankyou. Iv just found your channel, I am impressed..

[@SkunkieDesignsElectronics]

I'm not a fan of the "push open" ground connector, you can stick one leg of a spade and I don't think there is a "cover"

[@polkiju7]

Are you familiar with Broadcast phono preamps like Russco, Harris/Gates and Shure? I know that some use different impedance inputs compared to consumer pre’s.

[@SkunkieDesignsElectronics]

hmm no I'm not.

[@zoroluva]

Seriously loving these preamp videos. How does the "Color" preamp compare to these?

[@SkunkieDesignsElectronics]

The "color" pre-amp is a different animal, these are all RIAA pre-amps.

[@zoroluva]

@@SkunkieDesignsElectronics what?! Didn't even know there was a difference! I've still got so much to learn about tubes. Thank you for your videos. I've learnt so much from you.

[@ceylonmooney]

​@@zoroluva phono amp (aka phono stage, TIAA amp, phono preamp, phono section if its built in to another component) amplifies and EQs the signal coming off a record enough for a preamplifier to send to an amplifier. a line stage (aka preamp, control amp) sends line-level signals to an amplifier. the color preamp is a line stage. often preamps have a phono amp built in. calling a preamp a line stage means no phono section. a power amp (aka amplifier) makes the music loud enough to hear through speakers. a preamp & a power amp in the same unit= integrated amp an integrated amp with a radio or streamer = receiver the terms apply to both solid state, digital and tube electronics

[@zoroluva]

@@ceylonmooney thank you!!! I'm just getting into this hobby and my only references are a Denon receiver and a Aiyima A07 class D amp. Learning everyday.

[@raghavendramayya9902]

Is it silver mica or polystyrene mica capacitor which you replaced instead of disk mica capacitor ?

[@SkunkieDesignsElectronics]

www.skunkiedesigns.com/littlebear has a BOM

[@joenovak6393]

Nice content add I look forward to the Willsenton R300B Mod. I would recommend the Sunvalley SV- EQ1616D (DIY or assembled) as a Stereophile Class A recommended component for a DIY kit. Have a Nice Day!!!!

[@SkunkieDesignsElectronics]

Sadly, just a casual inspection I see a mess...

[@warp2600]

@@SkunkieDesignsElectronics which one is a mess? The R300 or the Sunballey?

[@SkunkieDesignsElectronics]

The R300. Just getting started with it and the power supply makes no sense...

[@warp2600]

@@SkunkieDesignsElectronics that's a shame, I had some good hopes for that one.

[@SkunkieDesignsElectronics]

I did too, it's not looking good :(

[@albanana683]

What would you use for a moving coil cartridge? Step up transformers or an extra gain stage?

[@SkunkieDesignsElectronics]

Absolutely a SUT, especially with a tube pre-amp. An extra gain stage would bring along too much noise IMHO.

[@albanana683]

@@SkunkieDesignsElectronics My preamp is solid state and only MM. I've tried a home brewed Lundahl SUT but it never sounded as good as running the MC into the 47K MM input and turning it up loud. I think I have an impedance mis-match somewhere but don't know how to track it down. Getting a good SUT set up is the first hurdle to moving to a tube pre-amp.

[@SkunkieDesignsElectronics]

I'm using a SUT from that Clayton guy who sells on ebay. www.ebay.com/usr/nclayton

[@VinylRescue]

After researching the parts from your BOM and the tubes you said sounds the best it comes to about $256 (with the Mundorf caps and the Electro Harmonix gold-plated tubes). I'm gonna order the parts soon so I can upgrade my T11 as you demonstrated. The 6N2 tubes sound good, but yes there is a slight hum in the background that goes away when the music starts.

[@ramenhausten]

Bless you for sharin the skunkie link. 🎉

[@jasonsorrels8388]

Do you have a list of the parts that you used for the Little Bear? I have one and would love to make these changes to mine.

[@SkunkieDesignsElectronics]

www.skunkiedesigns.com/littlebear

[@randomsuper]

great video as always. i have the ifi zen phono and can say without hesitation that it sounds great. i also have a dynavox tpr-3 tube preamp with a built in phono stage and for my taste, the dynavox sounds much better. it definitely colors the sound but in a way that i prefer. granted i upgraded the tubes but still. have you ever played with the dynavox unit?

[@SkunkieDesignsElectronics]

I would give the Zen phono around a 8 in this test. It sounds good but leaves some things on the table. It sounds better than the Little bear did out of the box, but the mod'd little bear def sounds better than it now. Never listened to the dynavox, what kind of tubes does it use?

[@randomsuper]

@@SkunkieDesignsElectronics it uses 2 6N3 tubes which i swapped out to GE 5670W. much better than what they came with for sure.

[@ericlane5949]

The 6SN7 is not a good tube for a phono section. Maybe they should be 6SL7s instead? I would try 6SL7s in it before dismissing it.

[@borissecluna5782]

It looks like thd middle tube is a 6SL7. It wouldn't make any sense to use a 6SN7 as a MM input stage. I wouldn't be surprised if CernTube screwed up the RIAA equalizer and ruined the sound. I built a Diego Nardi phono preamplifier that uses 12AY7, 6SL7s and 6SN7 in the line stage. Without a doubt, the best sounding phono preamplifier I ever built. Find the construction article in Sound Practices magazine.

[@garagepunkfan]

Since the Cern is wired point to point, why not try reproducing the RIAA equalization circuit outlined in the early 1960's RCA Hobby Circuits Manual? That circuit was specifically created to help sell the then-new 7025 tube to hobbyists and the industry alike.

[@SkunkieDesignsElectronics]

Just have too many projects going and the owner wasn't interested in doing anything with it.

[@PaulSelka-b9b]

What’s the cost of upgrades you did?😊

[@SkunkieDesignsElectronics]

Honestly, I'm not sure.

[@flyingmattyboy]

Steph I have built 3 x 834 clones on the douk board. All to the full Lenco Heaven spec ( including Thorston Loesch RiAA mods). The mods are easy to follow and the community is excellent. I have also included the alpha2delta psu in one of them. They all sound superb although I have used Russian 6n2p instead of 12ax7. I have never heard a standard one, I would love for you to build the Lenco version and compare possibly with the software and scope. In all three of mine the Hammond transformer has been inside a case with the tubes and they have all been quiet. I am im the process of modding one of them back to 12ax7, your de'soldering video on the Little bear motivated me to do it. Conell Dubillier Silver Mica's are the best value ones for the 834 I think. My last one has Charcrofts they are nice but they are £££ . Russion PIO caps sound nice in the 834. Good quality well matced RiAA resistors are needed too. Thanks for the videos, keepem coming.

[@rickg8015]

Yes, for RIAA resistors, the Dale RN60D/65D are nice.. The Takman metal films are detailed too without the edge.. I have seen TL’s 834 mod schematic years ago, but vaguely remember it.. I only remember him mentioning that the late Tim De Paravicini designed something really good with Active RIAA, even if Passive was more in vogue or something like that.. And now TL is busy with Ifi Audio, which is kinda cool cos’ the budget solid state phono unit in the shootout here is an Ifi Zen Phono..

[@flyingmattyboy]

@@rickg8015 I managed to get nos Holco resistors in the right values for the RiAA Thorstons mods. I bought a few sets at the time and used the most accurate pairs.

[@ceylonmooney]

stephe, i think u forgot the solid state phonos for the shootout

[@SkunkieDesignsElectronics]

I listed the one we compared these to in the description.

[@ceylonmooney]

@@SkunkieDesignsElectronics my word i TOTALLY missed that

[@1mctous]

Amir at Audio Science Review would not approve but most of your viewers understand why tube amps measure worse yet sound better. I think you're trying to say that the Little Bear and EAR provide a much better sense of the recorded space than a typical solid state phono stage.

[@SkunkieDesignsElectronics]

Yup!

[@NickP333]

Top notch vid, Stephe! I really wish the 6SN7 one sounded good too…. I’d love to get my hands on that one. I love 6SN7’s too. I’m in the process of building a “color” pre with them. I’ll let you know how it comes out. 👍😊 I had no doubt your EAR would win. Mine sounds fantastic. Great idea changing out those caps. You saved the Little 🐻 from a life of mediocrity. Did you try an MC cart with your SUT through any of em or did you just keep it MM? Thank you. Excellent vid 🔊😊🎶 P.S. I’ll send you a link to the toroidal transformer I used for my EAR if ya want. There’s a ton of great info on Lenco Heaven about modding an EAR, which definitely made an improvement. One of the things I did with mine was to put a 12AU7 as the V3 / cathode follower.

[@SkunkieDesignsElectronics]

Sure, send to my contact at my website. I can also connect you with the owner of that Cern pre-amp, he is interested in selling it now. I did keep it MM, using a AT VM540ML.