i have read through almost the entire thread now, took a few minutes.
Somewhere you wrote that the quality of the resistors, specially in the riaa part is very important.
How important are c1 and c2 then? I have not seen anybody putting in better parts there.
Is there nothing to gain to put in better c1 and c2, like silver mica or something like that?
I just noticed that there are many who spend big on c3 and c4, at the ps but never c1 and c2.
Dont forget: i am a total noob, so go easy on me.
regards,
John
Somewhere you wrote that the quality of the resistors, specially in the riaa part is very important.
How important are c1 and c2 then? I have not seen anybody putting in better parts there.
Is there nothing to gain to put in better c1 and c2, like silver mica or something like that?
I just noticed that there are many who spend big on c3 and c4, at the ps but never c1 and c2.
Dont forget: i am a total noob, so go easy on me.
regards,
John
i have read through almost the entire thread now, took a few minutes.
Somewhere you wrote that the quality of the resistors, specially in the riaa part is very important.
How important are c1 and c2 then? I have not seen anybody putting in better parts there.
Is there nothing to gain to put in better c1 and c2, like silver mica or something like that?
I just noticed that there are many who spend big on c3 and c4, at the ps but never c1 and c2.
Dont forget: i am a total noob, so go easy on me.
regards,
John
John,
Yes C1 and C2 are important too. They are low uF value caps and easy to come by in Polystyrene for those values. Polystyrene caps are cheap but very good.
I don't think silver mica caps are in the running for "high quality" RIAA caps.
Somewhere I posted some research on "boutique caps" identifying how that person ranked the "good" caps." No where did I see silver mica in the list.
This isn't the list, but discusses caps in general:
Audiophile Grade Capacitors
Of course roll with whatever you want to use. This is DIY so you can change them later to see what you like.
Rush
i have read through almost the entire thread now, took a few minutes.
Somewhere you wrote that the quality of the resistors, specially in the riaa part is very important.
How important are c1 and c2 then? I have not seen anybody putting in better parts there.
Is there nothing to gain to put in better c1 and c2, like silver mica or something like that?
I just noticed that there are many who spend big on c3 and c4, at the ps but never c1 and c2.
Dont forget: i am a total noob, so go easy on me.
regards,
John
The Vishays MKP1837 hold a really good 1% capacitor, so the capacitance does not vary too much therefore not tweaking the RIAA circuit sound. SO precision here is essential. Tone can be adjusted significantly by using C3-C4. I have noticed most tonal changes via C3 cap, which tends to be a little less expensive then the C4 cap. But that does not mean one should cheap out on C4.
Hi Rush,
I was just surpriced that nobody messed with c1 and c2 yet, but as mike said, it is about precision. Then it makes sense nobody did.
I have no clue what a better cap whould be and if there is, it would have probably been in there from the start i guess.
regards,
John
Hi mike,
I got a claritycap mr for c4 and audyn true copper for c3, not sure if i can justify spending more on those.
I did fancy a jupiter copper foil until i saw the price: 170.- a piece
dang, no copper foil for me. regards,
John
Hi John,
I did a quick search and am not seeing Polystyrene caps in the right values on Mourser or Digikey.
I bought 20 of each value back ten years ago and matched them as needed. Haven't had a need to buy more since.
I do see them on eBay, but shipping gets bad quickly.
I guess go with what you can get, Tea Bag had a good recommendation.
Rush
Hello Teabag
Do you mind telling us how you noticed the tonal differences via C3 ?
Do you have a rig for comparison ? Do you have any results like in measurements and anything to confirm anything changes with the change of C3 or other influential part? Or is just an observation after the exchange?
Its the lowest signal level AC coupling point in the circuit so it owes to be the most sensitive to loss or interference. Also watch the outer foil direction to be towards the lower impedance side of signal coupling. Meaning the C3's signal input side in this circuit. There are indifferent enough and quite sensitive film caps to outer foil. Depends on their construction.
Lots of wrong terms in that video but hear the difference in interference sensitivity
How to check for that on a scope
Lots of wrong terms in that video but hear the difference in interference sensitivity
How to check for that on a scope
Hi mike,
I got a claritycap mr for c4 and audyn true copper for c3, not sure if i can justify spending more on those.
I did fancy a jupiter copper foil until i saw the price: 170.- a piece
regards,
John
I did replace the C3 on my rig to Jupiter copper foil, noticed a big difference to the positive.
Replaced C4 to copper foil and did not notice an improvement. I have a couple of rigs and noticed each time changes primary when swapping out C3. I think the copper caps do sound good. My next comparison will be with the new CMR caps.
The clarity caps are very nice, and lean more towards robust but uncolored. I doubt I could pick anything up on a distortion rig. I have used one before testing the F6, and did not notice much difference is distortion pattern, but certainly the transformers all sounded different. Your mileage may vary as we say in US.
Not any more, and rare as hens' teeth too(*). Polypropylene / teflon / PPS film caps and genuine C0G ceramics are suitable replacements.
(*) Actually not it seems, but nowadays the packages are different - I can imagine why too, bare polystyrene is very sensitive to solvents.
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That would be a nice comparison indeed.
I read a lot about capacitors on the site from Tony G, he's done a lot of comparing, also the CMR caps, he seems to like them.
Humble Homemade Hifi - Cap Test
regards,
John
John,
That is the site with great cap reviews I was thinking about. I had forgotten which site it was, so great that you found it.
Rush
IT WORKS
no magic smoke, no drama, nothing weird, i am a bit confused about that.
adjusted to 3.6V no issues, but the rail voltage is a bit low maybe.
rail 1 is at 31.8V and rail 2 is at 31.6V, is this a problem?
The heatsink is not getting warm at all, ca 3 degrees over ambiant after 2 hours.
regards,
John
no magic smoke, no drama, nothing weird, i am a bit confused about that.
adjusted to 3.6V no issues, but the rail voltage is a bit low maybe.
rail 1 is at 31.8V and rail 2 is at 31.6V, is this a problem?
The heatsink is not getting warm at all, ca 3 degrees over ambiant after 2 hours.
regards,
John
At MM configuration it usually wants circa 32V rail. At high sensitivity configs it usually wants couple of Volt more.
About sinks temp being logical or not, let us know what is input raw DC, what is the leg to leg VDC on R1x, what is Vgs on Q1x Q6x.
Given the rail voltages respond to adjustment, that basically shows that the regs work normally nonetheless.
About sinks temp being logical or not, let us know what is input raw DC, what is the leg to leg VDC on R1x, what is Vgs on Q1x Q6x.
Given the rail voltages respond to adjustment, that basically shows that the regs work normally nonetheless.
Hi,
I would like to know if anyone listened the old version with 2sk170BL as input and the new one with 2sk369BL and tell me if it have a big difference between them, because I would like to try it but I can't find the fet of the new version.
thank you! Maxpou
Old version telescopic cascode with K170s is very nice but weaker for background clarity and firmness than the newer version folded cascode with K369s aka FSP.
For matched Idss genuine K369s ask Tea-Bag.
The picture says it all about why your sink is not getting hot. It is much-much more potent than the usual board level local small ones used. No worries about that then. Its good that it will not contribute additional closed box ambient temp delta.
Raw DCin voltage at 46.5V is a very good figure for this circuit again.
About regulated rails must be higher for 56dB there is no hard rule. It depends on Q1's JFET IDSS and R2 source resistor, also VR1 setting. Differs from build to build. If you set VR1 to full resistance it drops more to C6 front end rail voltage and the regulated main rail wants to go little higher to meet wanted T.P. for instance.
What is the DC reading between Q1 drain and GND right now?
Raw DCin voltage at 46.5V is a very good figure for this circuit again.
About regulated rails must be higher for 56dB there is no hard rule. It depends on Q1's JFET IDSS and R2 source resistor, also VR1 setting. Differs from build to build. If you set VR1 to full resistance it drops more to C6 front end rail voltage and the regulated main rail wants to go little higher to meet wanted T.P. for instance.
What is the DC reading between Q1 drain and GND right now?
Drain to gnd would be towards 8V. Those mV are source pin to gnd. In other words across R1. Meaning 8.29mA, 8.17mA Id channel 1,2. Enough and close together. Thus little lower B+ rail voltage needed to reach T.P. 3.6V is explained. If it was more Id due to higher Idss Q1 or smaller R1, more rail would be needed. The circuit is designed with such Idss and resistor values to typically balance well for wanted T.P. reading at no more than 9mA Q1 Id.
Your build works normally around its own tolerance of bias points due to its active parts tolerances. Watch your AC power wires dressing to be twisted and tacked away as far as possible to the opposite side of signal wiring and PCB so to avoid hum. All of them. Your R-Core transformers are good for low magnetic field emission but biggies. I hope they won't bother surroundings. The chassis work looks very good. Let us know your practical results about operation and sound quality.
Your build works normally around its own tolerance of bias points due to its active parts tolerances. Watch your AC power wires dressing to be twisted and tacked away as far as possible to the opposite side of signal wiring and PCB so to avoid hum. All of them. Your R-Core transformers are good for low magnetic field emission but biggies. I hope they won't bother surroundings. The chassis work looks very good. Let us know your practical results about operation and sound quality.