Search found 71 matches

by Naz
Wed Feb 28, 2018 1:08 pm
Forum: Phono
Topic: LCR Build
Replies: 11
Views: 13731

I've been too busy and haven't visited for a while but a good Italian friend alerted me to the thread. Very nice build and hope you enjoy it!

I have many iterations of the circuit now, PM me if you ever want to discuss.

Cheers,
Naz
by Naz
Fri Oct 24, 2014 5:18 am
Forum: Sim City
Topic: SET Driver comparison
Replies: 1
Views: 4942

SET Driver comparison

Guys, I recently got into a discussion (or argument depending on which way you look at it) on SET Asylum regarding which of these two circuits is best as a SET driver. I'm posting the ASC file here for ease of access and for anyone else who may be interested. I tried to set equivalent operating poin...
by Naz
Wed May 15, 2013 12:58 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Sorry Tony, It's been a long while since I posted and must have done something stupid in haste, happens as you get older :( I only have old schematics and will need to find the latest update but I'm happy to dig them up, scan and share with you. You are obviously much like me and always curious enou...
by Naz
Wed May 15, 2013 7:33 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

TonyB wrote:Hi Naz,

You mentioned a more complicated regulated power supply for your
Ref phono a while ago. Would you mind sharing its schematic?

I use RC tubed phono and am on 4th or 5th power supply. I always
want to try more.

Tony
by Naz
Wed May 15, 2013 7:28 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

bluesman wrote:Hello Naz or fvale,

Can this phono be built with balanced output? All phono cartridge is balanced by nature, so I am wondering if this is possible.
by Naz
Mon Jul 23, 2012 12:19 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Thanks Maturin, I personally haven’t bothered with differential Phono so can’t comment on the real vs perceived benefits except to say that for me, the added cost and complication of differential in general for other applications has not been worthwhile. I’m sure that it can provide an advanta...
by Naz
Sun Feb 12, 2012 11:02 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hey Drew (mate),

Just found the notification for this post in my Junk Mail, (went looking for it after receiving your PM).

As you can see up above Fabio has done a great job of his. So many options and suggestions ... a call is best to discuss, see PM.

Naz
by Naz
Wed Nov 02, 2011 10:48 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Much appreciated. I've spent more time on Phono than anything else in recent years because I love Vinyl and found that there is more to be gained at the front end than anywhere else. Besides, I have been extremely happy that I'm getting near enough as much as I can out of my PSE 845s, having spent y...
by Naz
Mon Oct 10, 2011 7:32 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hi Peter, Happy you are considering taking the trek, I'm sure you won't be disappointed. 2nd & 3rd stage triodes are individual halves. Using one tube for both bottoms and one for the tops makes it easier to elevate the top triode heaters but of course they either have to be the same tube type o...
by Naz
Sat Jul 16, 2011 11:28 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Not sure whether it was Bravi or Fabio who suggested trying 6S15P in lieu of 6C45P but I tried a couple and must say I was impressed and worth reporting on. Specs are the same but the pair I tried sounded a tad different. Perhaps not as quiet but VERY little in it. They are slightly more open, airy ...
by Naz
Wed Jun 08, 2011 8:32 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hey again Fabio, Connecting the bottom tube heaters to ground as you suggest is fine but it would still concern me a little having floating heaters (DC wise) on the top tubes using this method. I haven't tried it although in theory it should be OK. This is where the 6H30P excels with a whopping 400V...
by Naz
Tue Jun 07, 2011 5:14 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hey Fabio, 12V heaters is a good but since you have 3 stages a better option is to run all top tube heaters in series or parallel and elevate to 100V or so (a simple resistor divider connected to the neg terminal will do) and run all bottom tubes from a separate heater supply tied to ground. R8, 15 ...
by Naz
Mon Jun 06, 2011 1:33 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hi Fabio, Technically a 5687 will not be as good as a 6H30P in terms of ripple rejection and OP impedance. If you want to try it, instead of reducing the ref voltage, stick with the LM139 and increase the value of R2 (47K) to around 150K then fine tune to get approx 250V OP. You can use this method ...
by Naz
Thu Jun 02, 2011 8:45 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

About UX-280, I used two of them in the tube gain stage for my digital sources and got excellent performances, with a quite incredible sense of ambience That is exactly what I look for in a tube so they will be a great choice I'm be curious to know the reason you chose the 6H30 as many other tubes ...
by Naz
Wed Jun 01, 2011 2:48 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hi Fabio, Glad to have you on board, I'm sure you won't be disappointed. To answer your questions, almost any rectifiers will do. I haven't had any specific experience with UX280s but start with those if you have them, their specs are fine and they do look pretty cool! Ultimately, the sound quality ...
by Naz
Sat May 07, 2011 12:58 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Wow, nice trannie! The 6CA4 is more than up to the task and this is not affected by the size of the trannie anyway so only use something bigger if you particularly like it. One advantage of 720V ct is that you can go with choke input. Should be no need for a small input cap because it will increase ...
by Naz
Fri May 06, 2011 6:23 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hi Kevin, Good questions. The grid choke is a key feature of the design. To remove them would actually result in a ~2.5db cut at 20Hz, the response being flat down to 80Hz. It's impossible to cover every aspect in detail here, suffice it to say that if you were running sub(s) for extreme LF extensio...
by Naz
Wed May 04, 2011 6:31 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Dave convinced me to design my own LCR and suggested scaling it up from 600 ohm to 7K3 to make it easier to drive. In the end I chose a slightly different impedance so that I could use standard value caps. I'm glad I heeded his advice because whilst I approached the task with trepidation the result ...
by Naz
Tue May 03, 2011 11:20 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

No probs Kevin. To be honest I'm not sure of the exact specs for the power tranny I just used what I had, a toroid in my ref Phono and a standard EI for others. As long as it it can support the total current for the two channels with a healthy margin (100mA or so will do nicely) and provide the requ...
by Naz
Tue May 03, 2011 2:42 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hey Kevin, My personal Ref Phono utilises a very complex hybrid regulator with tube rectification, SS voltage ref and error correction with tube OP so I developed this simpler two tube version for other Phonos I've built and modified which works extremely well, not as accurate but very quiet and ver...
by Naz
Sun Mar 06, 2011 10:49 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hi Bravi, current through stage 1 is only about 7.5mA and a tad lower through 2. Stage 3 is running at about 9mA for lower OP impedance but could be taken as high as 15mA. It might appear strange running such low currents but linearity is not a problem with CCS, nor is noise an issue, even through t...
by Naz
Wed Feb 02, 2011 1:54 pm
Forum: Phono
Topic: Simple High Performance Tube MC Phono
Replies: 1
Views: 14813

Simple High Performance Tube MC Phono

Following on from my previous post on my Tube LCR MC Phono I am constantly asked for a simpler, cheaper version. Moreover what really prompted this post is that it bugs the hell out of me to constantly hear that no tube is quiet enough for MC amplification without the help of a SUT or Fet Cascode, w...
by Naz
Fri Jan 28, 2011 11:41 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

I've been asked several times now about simplifying the design by either substituting the top triodes with sand CCS or a simple Plate R. Here is a simple CCS version that measues well and I know works. Overall it sounds a tad thinner than triodes but subjectively quite detailed. Inreasing the idle c...
by Naz
Mon Dec 06, 2010 2:45 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

No probs Bravi, I finally got around to comparing sand CCS with tube. I never cease to be amazed how relatively minor differences from a technical perspective can change the sound so much. Subjectively a pair of Cascoded DN2540 Mosfets sounded a little more detailed than a 6922 on top of a 6922 but ...
by Naz
Thu Dec 02, 2010 6:10 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hi Bravi, First I'll bring you up to date with the SS CCS. Still haven't A/B'd SS vs tube but I have managed to get good results on another Phono using a generic feedback design. Had to increase idle current through the tubes to get some more body, used standard CCS on 1st stage and an R in series o...
by Naz
Fri Nov 12, 2010 2:22 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Funny you should ask, I've not actually tried it in this design but always expected it to work fine with little difference (and it certainly Sims well). However, I recently tried it in a generic Phono design that half the world seems to use and got mixed results that I still haven't resolved to my s...
by Naz
Tue Apr 20, 2010 12:20 am
Forum: Sim City
Topic: Generic ASC files
Replies: 11
Views: 18066

Dave, this is consistent with my findings in the real and Simmed world. Definitely worth a try and perhaps some experimentation with lower C and L values.

Naz
by Naz
Sun Apr 04, 2010 12:59 pm
Forum: Phono
Topic: Shielding LCR's
Replies: 14
Views: 11520

Andrew wrote:Hi Dave,

I'm hoping to get it all in, be a squeeze tho'. I'll post an image when its done and let you know if the hum is reduced.

cheers,

-- Andrew
I'll be very interested too Andrew. Are these for a 7K3 LCR?

Naz
by Naz
Sat Apr 03, 2010 1:01 pm
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Thought so, that's why I asked. You'll never fix it, ask me how I know! My original design had the LCR after the first stage. It hummed like a bastard even though the components were in mu metal cans. The only way I could overcome it was to place the LCR after the second stage, picking up near 30db ...
by Naz
Sat Apr 03, 2010 12:31 am
Forum: Phono
Topic: Real World All Tube LCR Phono for MC Without SUT
Replies: 58
Views: 110339

Hey Andrew, what sort of noise are you getting? If it's tube rush there's not a lot you can do other than use a different tube.

Naz