The AD797 in my setup was abit too clean sounding for my liking. Having tried discrete opamps successfuilly on my pMilette NuHybrid headphone amplifier, I decided to try out Bursons.
So you prefer the Bursons in your headphone amp. What is the improvement as compared to the AD797 in the phono preamp?
My feedback was specific to BursonV6 in my pMilette LR phono preamp. I had used another discrete opamp, OP01 (high output current) on my pMilette NuHybrid headphone amplifier.
I had tried default opamps on both with a Sennheiser HD-800S. As widely known, HD-800S can very revealing. In default opamp configuration, I find it too fatigue after 2 hours. With discrete opamps pairing, I find it specifically tuned and blended to my liking. Hard of give specifics, except that I had much longer sessions and listened to much more vinyl albums as a end result.
Still having the revealing, good sound staging characteristic overall but not over powering.
I finished mine last night - AD797 - battery powered. DC offset was no problem. I had some great support wiring the batteries correctly and once this hurdle was crossed.......simply music. I have tried two different cartridges so far (Ortofon SPU GM/E and Fidelity Research FR-1 MK1) and what I am hearing I like a lot - very open sounding, like a newly cleaned window - but not sterile or lifeless. So far I am very impressed indeed.
Initially I was somewhat disappointed with the sound, I'm using a Sumiko Blackbird cartridge which is the MC high output version. I thought the sound was to bright, I had R1 & R2 at 47K which is what Sumiko suggests.
I bought a pair of Burson V6 opamps, total waste of time and money as the DC offset wouldn't go below .450 mV.
I removed both R1 & R2 and soldered in pins to accept a 100K 25 turn pot. (This is a trick SALAS suggested to me when I built his FSP)
I adjusted the pots to 47K and installed them in the pins, I waited about 30 minutes of playing time with my wife listening with me. I then adjusted the pots going in the direction of an increase in resistance and within a couple of turns the sound had a very dramatic change in tone and sound, I set both channels to this setting and my wife and agreed that this was the best sound.
When I removed the pots I found the resistance was almost dead on 56K, I removed the pins and soldered in 56K resistors for R1 & R2.
Now I understand why everyone likes this preamp, it sounds as good and sometimes better than my FSP, UFSP and Threshold FET 10Pe.
Adjusting cartridge loading has made all of my phono preamps sound that much better.
I bought a pair of Burson V6 opamps, total waste of time and money as the DC offset wouldn't go below .450 mV.
I removed both R1 & R2 and soldered in pins to accept a 100K 25 turn pot. (This is a trick SALAS suggested to me when I built his FSP)
I adjusted the pots to 47K and installed them in the pins, I waited about 30 minutes of playing time with my wife listening with me. I then adjusted the pots going in the direction of an increase in resistance and within a couple of turns the sound had a very dramatic change in tone and sound, I set both channels to this setting and my wife and agreed that this was the best sound.
When I removed the pots I found the resistance was almost dead on 56K, I removed the pins and soldered in 56K resistors for R1 & R2.
Now I understand why everyone likes this preamp, it sounds as good and sometimes better than my FSP, UFSP and Threshold FET 10Pe.
Adjusting cartridge loading has made all of my phono preamps sound that much better.
Now that is interesting - I actually installed pins to give different values for R1/2 a try - quite interesting how the sound changes (having at hand 51K and 56K)...and I am sure this will be different from cartidge to cartridge as well.....
I am not sure I know how to do that.....anyway, how does one decide on the "correct" value? - I mean between those three resisors mentioned above I find it quite difficult to decide......🤔
The correct value is whatever you decide sounds best.
I recommend you get a pair of 100K 25 turn PCB pots and install them into your pins.
Play your favorite records and adjust the pots (remember which direction and how many turns). A second opinion will help and allows you to discuss what your hearing and not hearing.
Once you find the sweet spot, remove the pots and measure the resistance so they can be replaced with quality fixed resistors.
If you have more than one cartridge, repeat. When you swap cartridges in the future, remember to swap out R1 & R2.
I have a question to those running the unit off SLA batteries - when do you charge those? I have measured mine today and voltage input into the board is 9.5V.....
It sounds like it is time for a charge. Battery capacity will determine the length of time between charges. Usually, I go to a larger battery resulting in longer run time.
I've been reading through this thread and have looked at Pete Millett's site. I have been strongly leaning towards building this project, except for one issue.
Cost.
In order to complete this project, including the recommended enclosure from Landfall, (which on its own is over $250 USD) the potential expenditures are getting out of hand...
The Digikey Bill of Materials tops out at $200 Canadian for the power supply
The Mouser Bill of Materials tops out at $160 Canadian for the preamp itself
The enclosure is $340 Canadian
The PCBs from Pete Millett's bay store are $122 Canadian.
That's already $822, not including shipping, tax, and I haven't even heard back from Cinemag about the inductors.
At this rate I think buying a new Goldnote PH-5 is a viable option. It's a bit more money, but it has a warranty and real re-sale value.
Am I crazy thinking this?
Cost.
In order to complete this project, including the recommended enclosure from Landfall, (which on its own is over $250 USD) the potential expenditures are getting out of hand...
The Digikey Bill of Materials tops out at $200 Canadian for the power supply
The Mouser Bill of Materials tops out at $160 Canadian for the preamp itself
The enclosure is $340 Canadian
The PCBs from Pete Millett's bay store are $122 Canadian.
That's already $822, not including shipping, tax, and I haven't even heard back from Cinemag about the inductors.
At this rate I think buying a new Goldnote PH-5 is a viable option. It's a bit more money, but it has a warranty and real re-sale value.
Am I crazy thinking this?
How is that relevant?
Both are phono stages, trying to accomplish the same thing: high quality phono reproduction.
Both L-R and R-C have their upsides and downsides. Are you claiming one is better?
Both are phono stages, trying to accomplish the same thing: high quality phono reproduction.
Both L-R and R-C have their upsides and downsides. Are you claiming one is better?
Boy, can I relate! As you stated, the cost keeps rising with parts. One suggestion that I would have for you is to look at eBay a seller by the name of primetalproducts. They offer a half chassis, 2U enclosure that is about $60 shipped, and amazingly high quality. Aluminum is used for the front and back panels but the rest is steel. The finish is first rate. The Cinemag coils are probably $30 each and you might have to wait for shipping.
As it so happens, I have built 2 of these, and even may have an 'extra' set of boards if you are interested. I will go so far as to offer a built board and power supply if you like. I was on a mission a couple years ago and tried out one phono pre after another. I ended up building a very expensive (time and money) unit that has only been completed a month or so ago. Pretty much a nightmare, but it is up and running, hence the reason to put other stuff out there for sale.
FWIW, here is a shot of one of these enclosures being used for another project.
As it so happens, I have built 2 of these, and even may have an 'extra' set of boards if you are interested. I will go so far as to offer a built board and power supply if you like. I was on a mission a couple years ago and tried out one phono pre after another. I ended up building a very expensive (time and money) unit that has only been completed a month or so ago. Pretty much a nightmare, but it is up and running, hence the reason to put other stuff out there for sale.
FWIW, here is a shot of one of these enclosures being used for another project.
Attachments
For me it is! Dont bother! I wanted to say that the LR phono is special in regard of RIAA filtering! There are not many of that kind and you
should if you want this special phono not look thrue the eyes of cost only. Thats my point! 🙂
I used two AGM 12V batteries for a power supply = $45 from Amazon along with a $4 4PDT switch.
The enclosure from eBay = $60 shipping included
That's $431 less than your prices for the power supply and enclosure. You'll have plenty of time to shop around for low prices since Cinemag took 6 weeks to make the inductors for my build.