I have an SP14 Tubes4HiFi waiting for me to troubleshoot, might drag my Advent 300 upstairs to try. The problem is a little annoying but easily fixed by restarting the Aleph, so I'm more into listening to some LPs than troubleshooting 😉. That being said I'm really curious, as after 40+ years selling and installing A/V systems its pretty rare that I come across a problem that I have not encountered.
In the end it may be resolved and I never know what was going on, but if I can learn from the experience I'll count it as a win!
In the end it may be resolved and I never know what was going on, but if I can learn from the experience I'll count it as a win!
😆Yeah those things suck, haha, they take multiple cycles and still leave a mess. I consider this a real extravagance, but I'm worth it! Anyone who makes it 70 years on this crazy planet...like my dad always used to say, "Getting old is not for sissies!"
Have been using a spring-loaded manual desoldering tool for 5 years now and should investigate the gun above. Desoldering is always a sign of defeat for me and I hate it on so many levels...
And, yes, T4B and 6L6, it is a question of variance and the J112 could be specced for range variation and a better R choice made. Since the manual describes the values I experienced, as well as those reporting in the last 10 pages or so, it seems that a "safe" value could be substituted.
And, yes, T4B and 6L6, it is a question of variance and the J112 could be specced for range variation and a better R choice made. Since the manual describes the values I experienced, as well as those reporting in the last 10 pages or so, it seems that a "safe" value could be substituted.
Exactly as 6L6 said:
"The most immediate difference is the 1612 is bipolar input, the 1656 is FET."
That's one of the reasons I said rolling op amps not easy and not always compatible with the schematic.
Here - to name just a few things related to what has been just mentioned - different noise caracteristics depending on the schematic (keywords impedance, voltage noise, current noise) and also FET is per se usualy better suited regarding DC offset control etc.
Some builds aren't too much sensitive to the topology (my rig isn't, apart obviously from more noise or else related to THE op amp in use), some can just work with either type. My own RIAA preamp can just work with FET types, my DAC can work with either type (again, accepting the trade offs related to the... spec sheet).
P3... I don't know, but I can't remember reading it had to be one type or the other so may well work with either type and hence being quite friendly re amp rolling at least on the paper.
Why not using a DIP8 socket / adapter, try different Op amps (there are small non expensive boards enabling to fit ANY SMD op amps on DIP8, and obviously DIP8 just fit directly) and once you get one that ticks all the boxes for you either leave it (until the nest best op amp comes along LOL?) or just desolder the DIP8 socket and solder in place your favourite one (better for contacts etc., especialy if the socket has been (ab) used?)
That's what I usualy do and Jim & Wayne have been very cool by providing builders here on the board the choice to solder directly both DIP8 and most SMDs op amp sizes...
Have fun!
Claude
"The most immediate difference is the 1612 is bipolar input, the 1656 is FET."
That's one of the reasons I said rolling op amps not easy and not always compatible with the schematic.
Here - to name just a few things related to what has been just mentioned - different noise caracteristics depending on the schematic (keywords impedance, voltage noise, current noise) and also FET is per se usualy better suited regarding DC offset control etc.
Some builds aren't too much sensitive to the topology (my rig isn't, apart obviously from more noise or else related to THE op amp in use), some can just work with either type. My own RIAA preamp can just work with FET types, my DAC can work with either type (again, accepting the trade offs related to the... spec sheet).
P3... I don't know, but I can't remember reading it had to be one type or the other so may well work with either type and hence being quite friendly re amp rolling at least on the paper.
Why not using a DIP8 socket / adapter, try different Op amps (there are small non expensive boards enabling to fit ANY SMD op amps on DIP8, and obviously DIP8 just fit directly) and once you get one that ticks all the boxes for you either leave it (until the nest best op amp comes along LOL?) or just desolder the DIP8 socket and solder in place your favourite one (better for contacts etc., especialy if the socket has been (ab) used?)
That's what I usualy do and Jim & Wayne have been very cool by providing builders here on the board the choice to solder directly both DIP8 and most SMDs op amp sizes...
Have fun!
Claude
Congratulation on your 70´th B-day.
Not that different from me (going on 71 this summer)
I departed the "Spring loaded dingie" more than 40 years ago after destroying a lot of PCB-traces, when they were single sided crap.
Philips were the worst. Been using Solder Wick since, and just recently treated myself to one of these:
Desolder Station
and what a treat that was. It feels so solid, that it will probably outlast me.
Another Q for the bright guys @wayne , @6L6 and the likes........
Shitty weather yesterday, so I spent some time measuring and matching 100 pcs of 2SK209.
Although very similar batch, I discovered 2 distinct IDSS ranges. 2/3 were in the 6mA range, and 1/3 were in the 3mA range.
So now I´ve got a bunch of antistatic bags closely matched jfets in the ranges of 3, 5,9, 6,0 and 6,1mA.
I´m now planning for the next 2 builds of the Pearl-3.
My question: Is there any advantage/electrical or maybe sonic advantage in using one (3mA) over the other (6mA), and which group would
be best acoording to the original thoughts of the P-3??
I thank you guys in advance
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Perhaps one dual opamp that might appeal to some Pearl 3 listeners, is the AD746. It's the dual version of the AD744 singleton opamp, designed by Scott Wurcer. M2x builders recognize the AD744 as the opamp used in the wonderful sounding "Norwood" daughter card. Here's an image from the AD746 datasheet.
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