Tonight, I'm taking the TT downstairs onto my main system where it belongs. Tomorrow I'll properly fit the phono stage into my preamp case and use an off board supply.
I also order a load of those russian Silver Mica caps and also some paper in oil, thanks for the hint Salas. When they arrive I'll do a proper version, 'til then I shall be enjoying my already growing vinyl collection.
Regards, Lee.
edit: Surprising how it sounds with pretty standard parts isn't it Jonners?
I also order a load of those russian Silver Mica caps and also some paper in oil, thanks for the hint Salas. When they arrive I'll do a proper version, 'til then I shall be enjoying my already growing vinyl collection.
Regards, Lee.
edit: Surprising how it sounds with pretty standard parts isn't it Jonners?
jonners said:Here's a photo of my first attempt at putting a 'Salas Pacific' RIAA together. I've mostly just used R's and C's that were available at my local electronics store (Maplin), apart from the Audio Note output caps which I had already.
First impressions are favourable. The sound has more body and presence than before. 'Before' was with opamps: The Hagerman Bugle with LM4562s.
Thanks to Salas and all who have contributed to this interesting thread.
Hi!
I like dead bug ground plane constructions. So purely DIY!
Hagerman Bugle with 4562 is already a very high standard to surpass. We are doing well here I guess. What topology and gain version did you put together and what is your cart, arm, and TT?
Hi Salas, thanks for your reply.
The version I'm using is pretty much as your 'September 2008' but with a 33V supply and fixed source resistors of 39 Ohms, which gives Vd around 8V.
TT is Technics SL1210 with DIY PS upgrade, standard arm plus KAB fluid damper, Denon DL110. Haven't measured the gain, but it seems a bit less than I expected.
nicoch46 - Thanks for your tips. I shall certainly explore better parts etc and eventually put it in a box with decent wiring to the phonos.
John
The version I'm using is pretty much as your 'September 2008' but with a 33V supply and fixed source resistors of 39 Ohms, which gives Vd around 8V.
TT is Technics SL1210 with DIY PS upgrade, standard arm plus KAB fluid damper, Denon DL110. Haven't measured the gain, but it seems a bit less than I expected.
nicoch46 - Thanks for your tips. I shall certainly explore better parts etc and eventually put it in a box with decent wiring to the phonos.
John
found on diyaudio:
REgarding heavily loading MC carts - on this we agree. The 5 cartridge makers I know personally all said to me privately that they use 47k loading at home, in their own systems, but don't want to buck the writers upinions around loading. I strongly advise all our clients that they at least try 47k before killing the cartridge's life with a heavy loading.
Regards, Allen (Vacuum State GmbH)
----------------------------------------------end quote----------------
REgarding heavily loading MC carts - on this we agree. The 5 cartridge makers I know personally all said to me privately that they use 47k loading at home, in their own systems, but don't want to buck the writers upinions around loading. I strongly advise all our clients that they at least try 47k before killing the cartridge's life with a heavy loading.
Regards, Allen (Vacuum State GmbH)
----------------------------------------------end quote----------------
jonners said:
I have 2 SL1200 and I used one with the DL160. Very good match with the standard tonearm. For sure you are getting a bit less gain than expected bcs you use a bit less bias current due to 39R instead of 33R target trim value and, less than 36V PSU.
But the gain of my post#110 hand drawn schematic was too much for my 15dB line stage, 28dB amp and 95dB speakers. So I put it down to 40dB. That schematic is good for 0.5mV MC cartridges. Why you need so much gain with the DL110? Passive preamp? Single ended amp with less than 20dB gain? Maybe you drive less than 50k line in and you lose amplitude? You can add a buffer.
You must use a test record with 1khz 5cm/second lateral modulation track, and measure the mV RMS at the phono stage output, then divide by DL110's true 2mV. Log that number and multiply by 20. That will be the gain in dB.
I went to Michael's place today to measure and listen to his Salas 52dB cascoded version using the Salas shunt PSU at 38V. We could compare with the Steve Bench parallel 12AY7 and ECC88 cascode, which runs off a separately boxed high voltage PSU and Mosfet Maida reg. It has a hardwired Dynavector silver wire step up inside too. Both had shown same frequency response for the Benz Ace Low (Red).
The Salas phono output was 225mV for 1kHz 5cm/sec Telarc Omnidisc side 2 # 13 track. The gain looked to me suspiciously 3dB more than expected, but Michael informed me that the Benz Ace Red measures at 0.55mV. +0.15mV over its nominal output. 52dB then. As expected.
The phono alone THD was 0.07%. He did a very good job with modifying his TT motor bearings, and the rumble was -60dB unweighted on the silence test track. The Bench with step up, hit 56dB. We knew to keep it lower when comparing. Both units put out no audible hiss or hum or buzz. The shunt PSU was using small heat sinks and was just warm enough, not hot at all. The smallest one is on the CCS IRFP.
Salas + Shunt listening impressions:
I felt like it got 30% bigger stage than before. Bass was resolute and more present and pacey, but had natural decay. Could follow it very naturally. It was a new bass, like with master tapes.
Mids and highs presented such a non electronic tone along with strong image focus, like listening from a mic feed. The resolution was more than before, but it was not a separate thing. The musical interplay got very interesting now, from just very good. I felt happy about that because that was the main area that the Bench phono was standing out in comparison before the shunt addition.
VS Bench:
Curiously there was no comparison to make any more. The tube unit sounded thinner and narrower now. A bit of glare was its aftertaste. But its not the tube unit. Its an excellent unit. Its the new presentation of the Salas RIAA married with the Salas Shunt, that just points out electronic signatures of the other unit.
I have to make a High Voltage Salas Shunt for the tube gear. I feel like I am not comparing them fairly without.
The Salas phono output was 225mV for 1kHz 5cm/sec Telarc Omnidisc side 2 # 13 track. The gain looked to me suspiciously 3dB more than expected, but Michael informed me that the Benz Ace Red measures at 0.55mV. +0.15mV over its nominal output. 52dB then. As expected.
The phono alone THD was 0.07%. He did a very good job with modifying his TT motor bearings, and the rumble was -60dB unweighted on the silence test track. The Bench with step up, hit 56dB. We knew to keep it lower when comparing. Both units put out no audible hiss or hum or buzz. The shunt PSU was using small heat sinks and was just warm enough, not hot at all. The smallest one is on the CCS IRFP.
Salas + Shunt listening impressions:
I felt like it got 30% bigger stage than before. Bass was resolute and more present and pacey, but had natural decay. Could follow it very naturally. It was a new bass, like with master tapes.
Mids and highs presented such a non electronic tone along with strong image focus, like listening from a mic feed. The resolution was more than before, but it was not a separate thing. The musical interplay got very interesting now, from just very good. I felt happy about that because that was the main area that the Bench phono was standing out in comparison before the shunt addition.
VS Bench:
Curiously there was no comparison to make any more. The tube unit sounded thinner and narrower now. A bit of glare was its aftertaste. But its not the tube unit. Its an excellent unit. Its the new presentation of the Salas RIAA married with the Salas Shunt, that just points out electronic signatures of the other unit.
I have to make a High Voltage Salas Shunt for the tube gear. I feel like I am not comparing them fairly without.
I'm wondering about Obbligato caps for the 'Salas RIAA'. Has anyone tried them?
http://www.diyhifisupply.com/?q=catalog/23/obbligato_gold_premium_caps
John
http://www.diyhifisupply.com/?q=catalog/23/obbligato_gold_premium_caps
John
Salas
OK I'm ready to give up the tube in the second stage, have you tried the cascode, fet, zener in the second stage? I think I will keep the Pass B1 buffer-I like the current source in the buffer. Still shooting for as much gain as I can get. Did anyone use the cap bypass on the fet in the first stage (w/ the cascode-fet-zener setup)? I've never really liked a cap there, as you can alway hear it-maybe a black gate is the only thing I should use there if I do? Anyone have a few they don't need?
Also if you figure out a HV shunt reg, I would like to add it to my DHT line stage, which should make a big difference. Currently using a Lambda No. 28 tube reg with CLCLCL filter? Maybe I will try a version of the LV one with HV parts...who knows?
OK I'm ready to give up the tube in the second stage, have you tried the cascode, fet, zener in the second stage? I think I will keep the Pass B1 buffer-I like the current source in the buffer. Still shooting for as much gain as I can get. Did anyone use the cap bypass on the fet in the first stage (w/ the cascode-fet-zener setup)? I've never really liked a cap there, as you can alway hear it-maybe a black gate is the only thing I should use there if I do? Anyone have a few they don't need?
Also if you figure out a HV shunt reg, I would like to add it to my DHT line stage, which should make a big difference. Currently using a Lambda No. 28 tube reg with CLCLCL filter? Maybe I will try a version of the LV one with HV parts...who knows?
cygnus x1 said:
Yes, I have fully cascoded it too. Both stages. And yes the RC on the first stage is audible, that is why I did not recommend it to Lee and RCruz. But it is a matter of taste. Michael likes to play there for instance. Only the local shunts don't create buzz problems with all stages cascoded. Central PSU for the cascode bases is difficult to cleanly layout. The BC5550C base lends susceptibility to hum fields due to the strong hfe and bandwidth created. Needs the trafo in another box and careful shielding, cabling. I will try to figure out an HV shunt. It may work with just with HV parts as is. Do that if you feel adventourous, and see. Maybe with MJEs,or TIPs and HV Mosfets? It will be slower off course. HV bipolars dont have strong Hfe, but a Darlington pairing may do. But they will probably oscillate.
See the all cascode in the picture. Tell me the output of your cart, the gain of your line stage, amp, sens of your speakers and the size of your room. I will calculate the proper gain and post a fully cascoded for you.
Haven't compared, but ZenMod had mentioned that a Zener is even better there. I would try it current sourced and bypassed as in my shunt only though. Because it tends to LF pump without its own CCS. Have seen it doing it. Led string are another idea for Vref...
How is your sound by now it burned in a bit? What is your cart and TT and rest of system?
How is your sound by now it burned in a bit? What is your cart and TT and rest of system?
I am about to put together a maybe enhanced Led ref main feed CCS version tonight for my 40dB low B+ that I use for the Denon DL-160. It may be configured up to 36Vreg (up there the left hand SK still holds), by just changing the Vz and Vin=Vreg+6V. Ireg=(Vleds-Q1Vgs)/R1. Looks well trimmed and fast on transient simulation. Will see if it works OK. Its the glowing ''Simple Kitsch Shunt''.
Attachments
Salas,
System set up. Audioquest MC404I L -.23mV, VPI MKIII (stock AC motor-working on Maxon DC), DIY airbearing arm, Line stage- Type 340, CCs, ParaFeed OPT, PS Lambda No. 28 - Line stage gain- 24db, Amp 6SL7-6BL7-300b ParaFeed SET 7w/ch (gain ? have not measured), spks Fostex FE167-93db, room 12 X 20. I was trying to come up with phono stage with min. 50db gain.
System set up. Audioquest MC404I L -.23mV, VPI MKIII (stock AC motor-working on Maxon DC), DIY airbearing arm, Line stage- Type 340, CCs, ParaFeed OPT, PS Lambda No. 28 - Line stage gain- 24db, Amp 6SL7-6BL7-300b ParaFeed SET 7w/ch (gain ? have not measured), spks Fostex FE167-93db, room 12 X 20. I was trying to come up with phono stage with min. 50db gain.
The SET is the gain black hole most probably. They normally go 12-18dB. Since gain is better to be at the front end, here is what to try. Be careful, more susceptible to buzzes. Use NJFETs around 7.5 Idss because more will pull down VRL too easily, and less will rob gain. Good luck!
Attachments
Salas
Thanks, I'll give it a try. I did have a horn set up that was +98 db, but lost out when we moved and the wife did not like it in a finished basement. The amp had plenty gain for that setup and I had a Blue Point MC HO (got broke in the move).
I will also let you know if I come up with something on the HV shunt.
Thanks, I'll give it a try. I did have a horn set up that was +98 db, but lost out when we moved and the wife did not like it in a finished basement. The amp had plenty gain for that setup and I had a Blue Point MC HO (got broke in the move).
I will also let you know if I come up with something on the HV shunt.
