[theory_87]

ryuzoh, can you explain the switch inside? I switch all on as I do not know which is for Hi-C buffer.

I have install my own caps in. Currently using opa2134 in the amp, 2x 2stack buf634p as buffer and ad8397 as ground. Excellent sounding. will order ad8620 and 4x buf634u to try out soon.

 

[slwiser]

There is a way to make this four channel or three channel somehow from reading the main thread, maybe this is what that does.

 

[jamato8]

The fi.Q can be 3 or 4 channel. I like it better in 3 channel, which most likely is how you received it. The other two switches increase current but also increase distortion a tiny bit. I have all the changes somewhere but don't have it memorized. There are so many options. They will offer effects on different opamps that may work with one and not as well with another. It is like some of the tube equipment I made. I could vary the plate voltage, current etc., which allowed for different tubes to be used or fine tuning any one single type of tube.

 

[ryuzoh]

Very sorry for late and I'm modding 8 fi.Q's from yesterday and struggling to make guidances.

The switches on above side will set for......

SW1; BUF634 Wideband mode ON/OFF with 200 ohm connection btwn 1-4 pin.

SW2; Output impedance changing switch (aka A47), and will improve stability for unstable OPAMPs,
also changes proportion of output currents from buffers and OPAMPs.(Highly recommended to set this ON)
Output current proportion
When ON, OPAMP : BUF on front : BUF on bottom = 1 : 1 : 1 (OPAMP works 1/3), can achieve less distortion, stability.
When OFF, OPAMP : BUF on front : BUF on bottom = 1 : 5 : 5 (OPAMP works 1/11), can provide more driveability for low efficient headphones.

If you mind the hiss, are you using with default setting?

 

[jamato8]

Ryuzoh, you have your hands full!

The sound is coming in very well on the fi.Q. I have what, about 26 hours on it and the bass is smoothing out the the transparency is very good. I love the control it throws on any headphones I use.

I am listening to some Jerry Garcia, live from 1990. A out of print CD that is spectacular and the sound with the fi.Q is intoxicating. I can really hear the changes over the last 24 hours, which is to be expected.

 

[qusp]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif With nothing connected to the amp I don't hear hiss. All of my real testing equipment is in storage 1000 miles away. 9 tube testers, a capacitor checker for ESR etc that I love to use and other stuff. Well I got these ears. . . lol

ahem well I checked out your theory and there is still a small but still there hiss with JH13 and D10 off on low gain in the middle of the day. but seriously its really not worth mentioning, its quite low and disappears when music is playing. we all know how sensitive JH13 are so its not surprising.

like I said earlier, it may well be the metal cans anyway. i'm going out for Xmas lunch and the switch will have to wait till I get back. the fiQ sounds amazing and the hiss is less than Lisa, so i'm happy as larry, also the tweak potential satisfies another side of me VERY much!!

9 tube testers LOL

Quote:

Originally Posted by ryuzoh /img/forum/go_quote.gif [MG]http://www31.atwiki.jp/p3c-project?cmd=upload&act=open&pageid=1&file=4fiq.JPG[/IMG] Very sorry for late and I'm modding 8 fi.Q's from yesterday and struggling to make guidances. Will upload here below from now, please wait..... [IG]http://www31.atwiki.jp/p3c-project?cmd=upload&act=open&pageid=1&file=front.JP G[/IMG] [IG]http://www31.atwiki.jp/p3c-project?cmd=upload&act=open&pageid=1&file=bottom.J PG[/IMG]

nice big wacom Ryuzoh, I only have a 6 x 8 one but I love it.I had spotted all that stuff on the bottom, nice one!! i'll have to have a play with all that for sure. I think I prefer 3 channel too, wil see after I start my round of mods

I havent changed the position of the switches Ryuzoh, so whatever was set at the factory is how it is. I will check later on when I instal OPA827 and maybe try the buffers. I doubt it is on though , as I think I would notice 1:5:5 with JH13 lol. I dont mind the hiss mate, its really very minimal and I only mentioned it to be thorough with my observations, not because its bothering me

 

[ryuzoh]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif Ryuzoh, you have your hands full! The sound is coming in very well on the fi.Q. I have what, about 26 hours on it and the bass is smoothing out the the transparency is very good. I love the control it throws on any headphones I use..

Yes, and I'm getting awaken last 35 hours....
FGs will give more transparency until 100h by its thick foils like KZs.

Quote:

nice big wacom Ryuzoh, I only have a 6 x 8 one but I love it.I had spotted all that stuff on the bottom, nice one!! i'll have to have a play with all that for sure. I think I prefer 3 channel too, wil see after I start my round of mods

Thanks, coz my hands require longer stroke.
Looking forward to see your skyscraper

IMO, 2nd one from left is very good...combination of KW10000uF, KZ33/47uF, and ES47uF.

 

[shigzeo]

very nice manual Ryuzoh. And lovely pic!

 

[qusp]

Quote:

Originally Posted by ryuzoh /img/forum/go_quote.gif Yes, and I'm getting awaken last 35 hours.... FGs will give more transparency until 100h by its thick foils like KZs. Thanks, coz my hands require longer stroke. Looking forward to see your skyscraper IMO, 2nd one from left is very good...combination of KW10000uF, KZ33/47uF, and ES47uF.

yeah I still have an old A3 size wacom, but its quite old and only has serial interface lol, I dont need bigger than 6x8 most of the time, but ever now and then I wish for my old one to work. I use it all the time instead of my mouse, I have a stylus callous on my right wrist from the pad

I will take some pics of my new rig tomorrow. I have outfitted it quite nicely with a couple of new low profile mini2minis (for choice).

i'll go down and solder up some OPA827 in a moment, i'm finding that with my current combination I must have it in high gain or its lacking in dynamism and in particular low in bass. perhaps the LME49720 (for some reason I can never remember the national chips model numbers properly. one extra digit kills my brain

I think perhaps this chip needs higher gain to be stable, its like a different amp in high gain with this chip fitted. Nigel, have you tried the ADA4627-1BRZ in the OEM yet?

 

[SpudHarris]

I have indeed but to be truthfull the AD827's are doing it for me at present with stacked 634P's and a metal can 47910 in ground boy this is some amp......

Haven't tried any switches yet as I'm still not 100% sure of the likely changes. I will definately be following this thread to see what combinations you guys come up with. My amp is standard so imagine how stoked i am to know that better is to come when I get Ryuzoh to maxx it out for me. Don't worry Ryuzoh it won't be for a while yet

.

 

[theory_87]

Ryuzoh, may I know what is the bg resistor for r19?

I will put your post into the 1st page

 

[slwiser]

This is one sweet sounding amp as supplied with the default setup. I will wait till others do their experimenting to determine if I want to go away from the default. I am very satisfied with it as it is. I am interested in what the ADA4627-1BRZ does to the sound.

 

[theory_87]

My Current setup

The amp hiss with tf10p + 1 driver reshell and run warm...

 

[qusp]

its so hot here at the moment I wouldnt have a clue whether it runs warm or not

 

[ryuzoh]

Quote:

Originally Posted by qusp /img/forum/go_quote.gif yeah I still have an old A3 size wacom, but its quite old and only has serial interface lol, I dont need bigger than 6x8 most of the time, but ever now and then I wish for my old one to work. I use it all the time instead of my mouse, I have a stylus callous on my right wrist from the pad

Then iMate inevitable?

Quote:

Originally Posted by qusp /img/forum/go_quote.gif i'll go down and solder up some OPA827 in a moment, i'm finding that with my current combination I must have it in high gain or its lacking in dynamism and in particular low in bass. perhaps the LME49720 (for some reason I can never remember the national chips model numbers properly. one extra digit kills my brain I think perhaps this chip needs higher gain to be stable, its like a different amp in high gain with this chip fitted. Nigel, have you tried the ADA4627-1BRZ in the OEM yet?

Quote:

Originally Posted by slwiser /img/forum/go_quote.gif This is one sweet sounding amp as supplied with the default setup. I will wait till others do their experimenting to determine if I want to go away from the default. I am very satisfied with it as it is. I am interested in what the ADA4627-1BRZ does to the sound.

I already tried ADA4627-1(A and B), which gives precise sound stage and focusing 3D sound...I think this is so suitable with E8.
And LME49710/20 always go with this amp

Quote:

Originally Posted by theory_87 /img/forum/go_quote.gif My Current setup The amp hiss with tf10p + 1 driver reshell and run warm...

The pic shows imbalanced bypassing. And can see using FW10000uF/16V.
Also what are you using on G_CH? Why I didn't solder R19 (wideband mode resistor for G_CH) is, I couldn't find merit for using it;(
And as you know, OPs on there should be higher output current type.
I don't always recommend 4ch architecture, so that produces DC, and I received massages from Japanese users who says 4ch architecture will give hiss.
BTW, I think stacked 634 won't go with the wideband mode (SW1 ON) when portable use, of course will get warmer than LT1210.
Wideband mode will make it effective with single 634P and 634U.