AudioCircle
Audio/Video Gear and Systems => The Vinyl Circle => Topic started by: nlitworld on 6 Apr 2023, 12:50 pm
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So I finally decided to pull the trigger building myself a phono preamp kit. I have done some modifications to items but this is my first time building a full kit and having quite a bit of $ (for me at least) going towards it. I ended up purchasing a Vacuum Tube Audio PH16 pcb kit and transformer and I plan to have a SUT built inside with alternate inputs for MC and MM. I got this idea from the Don Sachs builds based on the same kits. I plan to do this build one time and deck it out right with nice upgraded parts (signal path caps, tubes, rca plugs, etc). Anyways, I know I'll be able to fumble my way through things, but if there's any tricks or tips you guys have that'll help, I'd love to hear them. My main concerns are if a barrier that shields the power is suggested (and SUT too I guess), suggestions for good shielded wire for signal wire, and suggested 6922 tubes.
My thoughts on a build list are as follows:
Main kit for most parts
VTA 1:10 SUT
Audyn True Copper Max signal path caps
KLE Perfect Harmony RCA plugs
Furutech FI-06 IEC connector
VH Audio Pulsar Cu II signal path wiring
Gold Lion 6922 tubes
Possible upgrade of resistors in critical areas
Thanks for all the help,
-Lloyd
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All your choices seem well thought out.
Make sure you have a good soldering station and use good quality solder. Wear shoes and have good ventilation.
Please follow up with your listening impressions. :thumb:
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Thanks Scott. Looking forward to this project even though I need a new project like I need a hole in the head. Just couldnt hang with a cheap phono stage anymore. Surprisingly enough and as much as I hate to admit it, with all the soldering stations I've used I go back to a good ol cheap Weller on a dimmer switch with Cardas solder. Works like a charm. I'll update with progress and listening impressions for sure. Gonna be good fun. :thumb:
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So I may have overlooked an important thing in buying upgraded capacitors. Apparently these Audyn caps are a twisted tinned copper wire lead and are too thick to fit into the pcb holes (1.67mm lead and about 1.0mm hole).
My thoughts to fix that is either untwist and separate some of the twisted wire or to snip the leads shorter and take some chassis wire that will fit through the hole and solder that onto the end. Any recommendation that I'm forgetting, I'm all ears. I could also try and return them to Parts Express and replace them with some Mundorf Supreme Silver as they should fit in the pcb holes without issue.
The one thing I don't want to do is use the basic Solen caps that came with the kit.
-Lloyd
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I wanted to update with a progress report on the build so far. I finally have all the parts and upgrades. I decided I wanted to build the kit with exposed tubes so I bought a Hammond chassis for it as well. All in all I have the power supply circuit board all complete. Circuit boards are actually easier to solder on than I thought. If progress continues at this rate, I may have it playing music by next weekend.
(https://www.audiocircle.com/image.php?id=252616)
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I'm eager to hear your thoughts on the sound. Keep us up to date. :thumb:
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This morning I was finally able to plug tubes in and flip the power switch. To my surprise, the tubes lit up and no capacitors exploded. I am getting some feedback from the SUT so I will need to sort that out though. I currently have my dac playing through a reverse riaa converter into the MM inputs, and it sounds phenomenal. Once I chase out that last bit of noise from the SUT, I think I will be a happy camper.
On a side note, those Audyn caps are just stupid big. It fits, but it's like squeezing a V8 into a Honda Civic.
For reference, here is a normal board
(https://www.audiocircle.com/image.php?id=252840)
And here is my board. :lol:
(https://www.audiocircle.com/image.php?id=252841)
Here is a peek under the hood. Can't see much but the SUT is still in an aluminum case, the transformer is in a steel cover, and an aluminum partition (hidden by the screwdriver) between power supply side and main board.
(https://www.audiocircle.com/image.php?id=252843)
And here it is all rocking & rolling.
(https://www.audiocircle.com/image.php?id=252842)
The hum from the MC input into the SUT is going to bug me though. I've seen a few different build posts about this kit where they put a SUT into the case just like I did here. The weird part is I have the MM input wires go into the case and connect at the SUT output. It only hums when the cables are connected to the MC input. I'll still check cables and all the lading settings to see if that changes things a bit. Not sure though. Even still, this thing sounds stupid good so far testing with my dac I put to it.
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I can confirm the hum is not due to SUT. Running the reverse riaa still had the hum into the MC inputs, until I grounded the little board to the phono ground. Then... silence. Sounds like I get to backtrack the hum (likely turntable chassis ground), but at least I narrowed down its origins.
After more listening this morning (and pardon my french) but holy shit does this sound good! Super clean, transparent and articulate sound. The drums really are more apparent with creating a true 3d soundstage rather than a foggy back of the stage. It adds just a tiny bit of that euphoric 3d effect without ever losing those low level details present when running the dac straight to the amp. Yup, I'm happy, even before this thing is properly broken in.
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Figured out ground noise issue to be a ground loop from cable shielding. Poked a wire in to touch the copper foil shield and attached other side to phono ground and it was silent. Since I didn’t install a ground lift switch anywhere, I'll be getting that permanently sorted soon having a ground drain wire attached.
It's broken in over 100 hours so far and the caps are starting to smooth out. I'll probably keep the reverse riaa on there for another week or two, then call it good. I'm sure just like with speaker crossovers, those big copper caps need lots of time to burn in.
To anyone reading this, I hope you enjoyed the progress reports. I had a lot of fun with this project and I'm sold, DIY is the way to go. I get to tinker AND I get better sounding equipment. 8)
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Hi,
Thanks for the post. I'm so envious of your electronic skills. Happy listening :)
Cheers Rod
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Hi, If you are looking for MC. Then go no further than the one developed on Audio Karma by member HypnoToad. Its the AD797 phono amp. Boards & build boards with an absolutely deed quite P/S are available from another member Sachu888. It has adjustable gain and capacitance & gain handle very low output MC around 0.1mv. This unit will easily trade blows with any $5000 commercial phono amp
Cheers
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Lol.
"Donny, you're out of your element."
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Hi, Can you solder a lead to RA's,
If not learn how to do this.
If yes, then you can assemble the AD797 P/Amp, because you can buy a built up board that only needs assembling in a case & then add the RCA connectors'
Cheers
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Well done Lloyd! Congrats on the project. I know by experience it is a bit of work, thinking and planning these things out. But it is fun work! I am currently in a build and have a few days just researching parts. Also not cheap as things add up quick. However, the level of performance can be stunning. Then when you factor the level of performance in an equivalent in build of a commercial product, its a beautiful thing.
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But it is fun work!
Thank you for the compliment. I had a great time building my kit, and I can't recommend that type of project enough. I got to tinker in the garage for a week and then my end result is better music reproduction. Win, win right there. And yes, when you factor commercially available units vs my cost/time investment, I'm still way money ahead.
I'm going to pull things apart a little bit and swap a loading resistor to better match my cartridge, so when I do I'll post a better photo of the internals if anyone is interested.
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Last night I was enjoying a few records and heard a big "pop" from the right channel and didn't notice immediately, but it appears one of the tubes went out. The tell sign besides no music from right channel was the top spacer glowing red. Luckily enough the timing still puts it under warranty for a replacement. This did get me thinking about having some backup tubes for the "in case @#!+" purposes. I have been enjoying the sound of the Gold Lion tubes which are very clear and articulate, but is there anything better? I know of the Reflector 6H23P but I've heard that is even a little leaner than the Gold Lion. Would anyone suggest a different tube via a socket adapter? Overall I'm happy with the sound, but in true audiophilia fashion I always wonder what else could be better.
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There are A LOT (!) of 6922 and ECC88 tubes out there. It's quite possible you'll discover something that everyone rejects (and therefore is cheap), works like a charm in your customised preamp. You can only know by trying in your setup. Really something to look forward to and enjoy . :popcorn:
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This is a cool topic!
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No brainer Pass DiY Pearl Fantastic,
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Thought I'd give an update to close this thread out for a bit. I did in fact have a tube go poof, and Upscale Audio was fantastic to rush me a replacement. Phono stage is fantastic and getting several hours of use per week. I emailed Brent Jesse about some tube upgrades and for what I'm looking for he recommended some Amperex or going big $ some Mazda 7308. Probably for Christmas I'll pull the trigger on some tubes and maybe a couple more small capacitor upgrades in there.
I did mess with the loading resistors and went with Vishay z-foil resistor that I matches specifically to cart and SUT performance. Definitely an upgrade over the basic resistors from the kit.
All in all, this thing is phenomenal. I can't say enough good things about this kit or the service from Tubes4HiFi. Definitely a :thumb:.
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Not sure if anyone was following this thread but here is an update since I'm wide awake at 1:45am listening to music. I decided to do some work on this phono preamp a little bit ago. My goal was to update into a smaller chassis where I went from a 17x13x4 down to a 14x10x3 unit. My other goals were better solidifying component placement, shortening signal wires and borrowing some upgrades used on the Don Sachs units. End result is still great sounding but considerably better soundstage depth, and way better chassis size to fit in my small room. The only thing I gave up for the small chassis was the center partition between power side to signal side.
(https://www.audiocircle.com/image.php?id=263457)
(https://www.audiocircle.com/image.php?id=263458)
Again, if anyone is contemplating a build of anything Tubes4HiFi sells, I wholeheartedly say jump in head first. These kits absolutely rule. :thumb:
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Hi,
Thanks for the update. Happy listening to your phono stage :)
Cheers Rod