Unless you have access to some strange naked vishays their lead spacing is 5mm.
0805 resistors can be mounted too, btw Panasonic ERA are available as 1206 390R and should be pretty similar to Susumus.
Interesting. I was looking at the Vishay VAR datasheet through a link from PartsConnexion. It specified lead spacing of 3.81 mm, seemingly for all VAR.
The Panasonic ERA may be a good sounding thin film. That said, it's current noise constant is roughly 2e-8. Again, reading from a graph and converting.
Jac
No !
ADD a pad at 3.8mm (or 3.81mm) so that builders have the option to use 0.2", or 3.8mm, pin pitch.
It's the same recommendation that I keep barking on about for capacitors. Provide choices for pin pitch.
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voltage distortion can be a problem. But usually is so low that it can be ignored after the designer has checked the voltage rating.
It is very easily solved.
Use two, or more, series connected resistors. This reduces voltage distortion. It also reduces temperature induced distortion.
This is more usually applied to the NFB upper leg resistor/s that can have very many volts applied to it/them !!!!
I have already presented in this thread my personal constructive solution of the Fremen, so do not add anything.
http://www.diyaudio.com/forums/chip...-edition-rc-build-thread-125.html#post4060850
However, I am speaking now to put in sharing my impressions after making some changes in the components strongly suggested by my friend Dario Inserra (ClaveFremen).
The members who took turns to previous were at the time as follows:
-ERO 1834 150 pF (C 32)
-ERO 1834 10 nF (C 7)
-Black Gate 220 mF / 50V Standard (C 9 )
They are waiting for me to arrive Riken 390 Ohm
It would need to wait many hours of operation of the amplifier to have a stable framework of changes in the sound after the "surgery".
However, in my perception changes are very clear and obvious.
Greater transparency and detail. An incredible force of the bass range, more articulate, powerful and deep, without smudging. Midrange very convincing and rich. The treble in the early hours resulted at times a bit 'edgy but after some hours of running this feeling has disappeared.
The focus and perspective reconstruction is especially remarkable in the depth of the scene. As the hours passed all these elements seem to be evolving positively.
I am extremely pleased at the conclusion of the overall performance of this amp that doing nothing but amaze me all the time. My reference amp has always been my homebuilt OTL in Circlotron configuration (two mono blocks, with 4 6C33C). The Fremen looks good in almost anything compared to him. The most obvious attribute is its neutrality and in my opinion this is a huge honor.
I will refer 'soon will come into play when the Riken and beyond when ride on the MLytic Mundorf AG (10000 mF / 63V....mmmh!! my money).
http://www.diyaudio.com/forums/chip...-edition-rc-build-thread-125.html#post4060850
However, I am speaking now to put in sharing my impressions after making some changes in the components strongly suggested by my friend Dario Inserra (ClaveFremen).
The members who took turns to previous were at the time as follows:
-ERO 1834 150 pF (C 32)
-ERO 1834 10 nF (C 7)
-Black Gate 220 mF / 50V Standard (C 9 )
They are waiting for me to arrive Riken 390 Ohm
It would need to wait many hours of operation of the amplifier to have a stable framework of changes in the sound after the "surgery".
However, in my perception changes are very clear and obvious.
Greater transparency and detail. An incredible force of the bass range, more articulate, powerful and deep, without smudging. Midrange very convincing and rich. The treble in the early hours resulted at times a bit 'edgy but after some hours of running this feeling has disappeared.
The focus and perspective reconstruction is especially remarkable in the depth of the scene. As the hours passed all these elements seem to be evolving positively.
I am extremely pleased at the conclusion of the overall performance of this amp that doing nothing but amaze me all the time. My reference amp has always been my homebuilt OTL in Circlotron configuration (two mono blocks, with 4 6C33C). The Fremen looks good in almost anything compared to him. The most obvious attribute is its neutrality and in my opinion this is a huge honor.
I will refer 'soon will come into play when the Riken and beyond when ride on the MLytic Mundorf AG (10000 mF / 63V....mmmh!! my money).
Do you know which of the three changes produced the audible difference?
Did you do any measurements after each change was implemented?
Did you "run in" the new component/s before listening to the "new" sound to avoid your ears/brain becoming acclimatised to the "edgy" sound?
For my choice and convenience (I have little time) I ran the exchange of all three components together. I did not have measures except the offset (0,8 mV in both monoblocks). The changes in my view are obvious.
The impressions of some harshness in the treble were confined to the first few hours of listening, then I left to work in the amp loop signal and I repeated listening after about 24 hours. Those hardships were already gone. Curious to find out that there will be changes with the Riken.
You will see below.
The impressions of some harshness in the treble were confined to the first few hours of listening, then I left to work in the amp loop signal and I repeated listening after about 24 hours. Those hardships were already gone. Curious to find out that there will be changes with the Riken.
You will see below.
I do not understand: I have no problem. I simply reported as positive has changed in my perception of sound after replacing the components of which I have reported.
Prior to the amendment the amp was fine and I was happy.
I wanted to make this modification work and I perceived clearly a significant performance increase listening. everything here
At the present time known that the increase is still evolving positively. Go better and better and I'm excited about it.
My friend, it is not difficult to understand what I said and I have no hallucinations.
in the early hours of listening, after the changes, I felt a treble at some time a bit rough. Subsequently, after approximately 24 hours of operation of the amplifier, this perception has completely disappeared.
It 'clear now?
Maybe my English is bad, I hope you will forgive me.
Sontero,
Thank you for your impressions. I built mine with the ERO from the start, so I never got a chance to hear their contribution. I have tried some non-Black Gate caps at C9, so I suspect (as does Andrew) that the electro at C9 may have caused the early harshness and, IMO, was probably the biggest contribution to the change in sound of the three you changed. Of course, how would I know? I just said that I went straight to the ERO caps in my build.
For others that would like to try the ERO caps, I just bought some from "Paradise of Hi-End Audio Components" or umut1001 on ebay. He has great service and good prices.
Jac
hi lehmanhill
I can not say which of the three components has made the greatest contribution to
the wonderful change now, however it does not seem a problem.
I believe, however, that the greater percentage is paid to the Black Gate that
notoriously must work many hours before stabilizing and in fact
in the early hours almost regretted the Nichicon FG before this.
It seems less likely that the ERO they need prolonged use to get up to speed.
The most remarkable non-BG cap that I've heard at C9 is the Nichicon UD 220uF/50V. It rivals or surpasses the BG-PK and Nichicon KZ, but I haven't compared it with BG STD.
(However, this was not in a MyRef FE - if somebody has an FE and the patience to try it out, I'd strongly recommend trying the Nichicon UD. It is not harsh at all, and has relatively high measured ESR of ~1.3 ohms. That is the crucial ingredient in taming the harshness of C9, IMHO. No bypass is required - but if I had to use one, I'd go with a small Wima FKS or ERO KP1830 of the order of 10 nF.)
Typo - that should read as 0.13 ohms or 130 mohms. It's still higher than typical low-ESR electrolytics with ESR in the sub-50 mohms range.
I've finally finished (well, almost..) enclosing my FE! I used a 2U Dissipante case from Hifi2k, was a bit of a pain to mark the holes in the heatsinks but it looks pretty good now. I messed up on the hole for the right LED, you can see some scratches around the bezel. I'm gonna get a washer to cover it up.
For the input caps, I'm using the Russian K71-4 - I'm still waiting on some conductive copper tape so I can ground their metal cases, they cause an ugly buzzing with disconnected inputs.
The case is also not grounded yet, I forgot to order resistors and capacitors to make ground loop breakers, I'll pick those up locally soon.
And most importantly of all, it sounds great! I'll have to compare it to my P101 when I'm done rebuilding that.
For the input caps, I'm using the Russian K71-4 - I'm still waiting on some conductive copper tape so I can ground their metal cases, they cause an ugly buzzing with disconnected inputs.
The case is also not grounded yet, I forgot to order resistors and capacitors to make ground loop breakers, I'll pick those up locally soon.
And most importantly of all, it sounds great! I'll have to compare it to my P101 when I'm done rebuilding that.
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