After a few days listening to the RIAA, I can say that I am really happy with the final result. A big improvment from my previous non cascoded build. More dynamic, more resolution, more 3D sound, more of everything. Also it is very balanced. It' s like having another stereo! It was well worth the effort put in building it.
Also FYI, I changed to battery bias bias and put an 470nF FT-3 output cap (I liked this very much! I would like to have a similar value of Mundorf silver gold oil to compare. It is going to be difficult to better it.) on my #26 pre and things improved even more.
Everybody serious about records should give this a try. It' s one of the best sounds I ever heard.
Also FYI, I changed to battery bias bias and put an 470nF FT-3 output cap (I liked this very much! I would like to have a similar value of Mundorf silver gold oil to compare. It is going to be difficult to better it.) on my #26 pre and things improved even more.
Everybody serious about records should give this a try. It' s one of the best sounds I ever heard.
Attachments
the blue wires were temporary are they are removed now, as I run a seperate ground wire from the PS box. The picture is from yesterday.
As I have two big 10H chokes, heater pregulation with 2x15000uF per channel, 3 transformers, 2 anode chokes and 2 SSHV, I do not think I can do one box!
This was morphed from my previous 12b4 pre, so there are a few extra holes!
As I have two big 10H chokes, heater pregulation with 2x15000uF per channel, 3 transformers, 2 anode chokes and 2 SSHV, I do not think I can do one box!
This was morphed from my previous 12b4 pre, so there are a few extra holes!
To aid ventilation, you planned it all along.
What kind is that cotton jacket(?) twisted pair wire you use for linking the phono output to the boards?
Tryed with 220R Caddock MK132, 1st impressions is that the sound has more punch or dynamics so more mids & lows also more noise than the Vishay Tx2575 but can't come back to 150R, when I have the money I will order 220R Vishay Tx2575 to Michael Percy. Thank you for great input Nick, now is time to tweak the Riaa HF cap so I will change 15nF76 SM to 15nF teflon film & foil, I will tell you what happens....
To aid ventilation, you planned it all along.
The ouput wire must be shielded
OK. Keep 150pF extra caps to make tuning steps. VG's 15mA Vjfet custom simplistic lends it self for 15n straight Teflon by its intrinsic alignment I used, yours may need a bit more than 15n or not. You will see.
No if you don't get any buzz noise. You get any? You got no Tx in that box at least.
I have a couple of shielded interconnects which seems to me less dynamic than the ones, pure silver, that I am using now. With the tubes, there is slight buzz only listening right at the speaker. I am certain with different tubes and a little work on layout can make things better. Tape noise from analogue recordings is a lot louder.
For the moment I am listening one of the best sounds ever listened.
For the moment I am listening one of the best sounds ever listened.
vgeorge,
Nice build by the way. thevery slight buzz could be a bunch of things.
If you look here: http://www.diyaudio.com/forums/tubes-valves/178027-gyrator-frequency-response-6.html#post2384228 some of your perception may be found. Sheilding adds alot of capacitance, and resistance plays a role as well. In this post I was playing with attenuation and cable length.
Nice build by the way. thevery slight buzz could be a bunch of things.
If you look here: http://www.diyaudio.com/forums/tubes-valves/178027-gyrator-frequency-response-6.html#post2384228 some of your perception may be found. Sheilding adds alot of capacitance, and resistance plays a role as well. In this post I was playing with attenuation and cable length.
If you use twisted pair you are adding capacitance also....if you use parallel wires it's capacitance symbol so exist also capacitance, less what still have...so doesn't exist a couple or more wires without capacitance, you can minimisize the effect if you use a Litz geometry or separate with the maximum lenght possible the wires (this last one difficult to do for chassis wire)
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