• Disclaimer: This Vendor's Forum is a paid-for commercial area. Unlike the rest of diyAudio, the Vendor has complete control of what may or may not be posted in this forum. If you wish to discuss technical matters outside the bounds of what is permitted by the Vendor, please use the non-commercial areas of diyAudio to do so.

AudioSector-chip amp kits, dacs, chassis

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
The 48VA Hammond transformer is ready for dual voltage operation and the board allows switching, by using jumpers.

The board is completely self contained: BNC and RCAs are mounted directly, as well as AC recepticle. The fuse is soldered underneath. Basically you can mount it on a plank of wood (BTW it sounds best this way) and it's ready to use without ned for chassis. That's actually how I'm using it presently, as it does not need additional shielding.

I should be picking the boards middle of next week.
 
Initially I was using 2 x 10V AC, but that required removing some of the windings in the receiver section (as the voltage was a bit high for those Panasonic regulators). Later I tried 2 x 8V AC, and it seems to be working fine with both sections (receiver, DAC) without need for modding. So any transformer producing 8V AC should be fine. Please note that there is some voltage drop on series resistors (1V or so)

I was also considering partial kit, with hard to get parts. Some of those parts are simply necessary for best sound and one shouldn't skip them ;)
 
Peter Daniel said:
Now the best part. As I mentioned already somwhere else, I'm not that crazy about snubber anymore, and prefer not to use it. I'm getting very good results with AC power and single 100u BG N caps, but with some efficient speakers it may create slight hum of the drivers, or some might prefer more substantial bass signature. So I made extra holes for 1500u Panasonics which can be used together with those 100u caps (preferably BG N) on amp's board. Also, when snubber isn't used, variety of bypass caps are possible to mount in that place, with spacing ranging from 200-400mil.

So Peter, what are you recommending for caps nowadays? Non-BG of course, I'm not there yet :) If I understand correctly, no snubbers, 1500uF FC's on the PS boards, and 100uF FC's on the main boards?
 
leadbelly said:


So Peter, what are you recommending for caps nowadays? Non-BG of course, I'm not there yet :) If I understand correctly, no snubbers, 1500uF FC's on the PS boards, and 100uF FC's on the main boards?

Actually, at present, I'm using 100u BG N only, no other bigger caps. But this may not work well with all setups; easy to drive speakers, preferrably full range are rather recommended.

With regards to snubber, as some of you noticed, I got excited initially as well, as it dfinitely made a difference, and sound was more distinct and grabbing. Yet, my subsequent test show that everyhting was not right with a snubber, and ultimately, snubber is not an actual improvement.

As I designed the amp modules for those two way active speakers: http://soundfusion.ca/download/speakers.pdf , it was in my best interest to try improve on the original design and last weekend I took with me all popularly used capacitors as well as some snubbers and tried to prersent the new ideas to the makers of the speakers. The listening room was pretty well tuned and basically devoted to listening sessions only, with round wall behind the speakers and special damping panels all over. The source consisted of modified Shanling.

We were listening to various caps configurations and also snubber with big caps (I used very good 4 pole Jensens here). The snubber was rejected immediately. I could also clearly hear its inferiority. The sound was lacking air, top extention, bass became slow, lacking texture and snap.

We pretty much liked Panasonics, as they were quite musical and not boring. Interestingly, 1000u BG N were also rejected as sounding too mellow and tubey (those caps were pretty well broken in, as I was using them previously for half a year). Rubycons ZL had nice tight bass, but the tonal balance was shifted up and it didn't sound right.. Nichicons KZ were overall rather neutral, but lacking that special something that makes you want listening to the music.

According to the listeners in that session, 1000u BG STD were absolutely best choice: fast, detailed, extended, with proper tonality. To me, on more complicated passages the sound became a bit less organized with traces of harshness could be observed, but this didn't bother the other two guys.

We also tried 100u BG N by itself only. They didn't sound as good as in my system (but the speakers here were rather hard to drive, with 4 ohm impedance and 3rd order networks). They were distorting in bass a bit when pushed, and tonality was on a smoother side with sort of tubey character. For some it may be preferred choice but my two friends were into faster sounds and didn't like it that much. However, adding 1000u BG STD at the bridges (with 2' umbilical to the amp) fixed things substanially and it was pretty good combination (although they still claimed 1000u BG STD at the amp was better). It is not better to me, when I listen at home though ( and my speakers are very easy load).

So my current conclusion is that if BG STD 1000 seem harsh to you and you need more smoothness, add 100u BG N at the chip and use the other BG at the bridges.

If you need extra clarity and harmony with really delicate sound signature, no sign of harshness or brightness, you listen only at moderate levels on efficient and easy to drive speakers, and your material does not consist of Transe and House music (although it's still works for me) you might as well give a try to BG N 100u (only) and see how they perform. You can always add more capacitance later.

But the single, overall most universal choice, something I would use commercially, would be still 1000u BG STD (and no other caps).
 
Peter Daniel said:


We were listening to various caps configurations and also snubber with big caps (I used very good 4 pole Jensens here). The snubber was rejected immediately. I could also clearly hear its inferiority. The sound was lacking air, top extention, bass became slow, lacking texture and snap.


So was all this rave about the snubber just builder's bias and excitement? How could your listening group dismiss the snubber so easily without even a hesitation and all those people who tried in from this forum rave about it?

Im really disapointed to hear this as i had an integrated amp planned around the snubber, and im sure Brian is too with all the time he has invested behind this snubber idea...
 
Ex-Moderator
Joined 2002
Homer

The one thing that I have learnt from GC building is that they really do have to be tuned to the system, and to your own ears. Generalisations just don't work. Just build a few and play, and make your own mind up. I respect both Peter and Carlos a lot, they have both contributed much to the field, but if it came down to a final choice, I would still go back to my inverted OPA549s with ZLs, Wimas, and Dales. This is not that the others don't sound good, they do, in fact the 4780s are excellent, but the OPAs do it for me, in my system, and my enviroment.
 
Homer,

Well, I was almost ready to invest in the snubber myself, and was already considering the purchase of big Nichicons from Percy. I also made comments that this was an improvement.

However, in the light of recent experiments, I feel oblidged to report on my findings, as the previous ones might have been misleading.

I can suspect that snubber performance might greatly depend on the system, personal preference and listening education. I'm merely reporting the findings of people whose judgement I trust, and whose advice was always helpful in developing of my designs.

As usually, everything has to be tried personally, but I was already receiving numerous comments from other people, using premium kits, and they also did not like the snubber.

You shouldn't be disappointed with my comments, as I'm merely reporting findings I've heard from others, (as well some of my own). However, I cannot recommend something that I don't like myself, and I feel it's appropriate to let everybody know about it. Yet, on my boards, there is a place for the snubber, so if someone likes it, can also use it.

I believe the time I invested in the snubber, isn't any less that what Brian invested. And I actually listened to the snubber before implementing it on my boards.
 
Pinkmouse is right.

You have to judge for yourself and make decision. Even with my listening buddies, we sometimes not agree about certain aspects, as everybody has personal preferences. Sometimes, I may not agree initially, but later it becomes obvious that I was wrong. The main idea is try things and develop your own taste, not blindly follow others. And learn how to listen. When I look back, 3- 4 years ago, my preferences were completely different than what it is now. Not that it will stay the same also, it's a constant journey with no end on horizon.

Remember those swithes in older equipment ( called lodness)? The snubber does very similar thing. Did you ever see loudness switch on high end equipment?

I still use loudness in my ghetto blaster though ;)
 
Yes your both right Pinkmouse and Peter. I was disapointed only because the snubber seemed like an exciting new sure bet, but like pinkmouse pointed out, there are no sure bets in DIY audio.

So, since this choice comes down to preference and environment, what capacitance setup would you recommend for me (10 000/1000/100), im a bit unsure after reading all yer findings what setup favours what preference. Im using 90db book shelfs at the moment (Athena AS-B1), I listen mostly to alternative rock, heavy rock, progressive metal, house and some trance. I appreciate well defined base with punch and dynamic highs over smooth tubey sound. I like my mids clear with as much detail as possible (i love hearing new things in my recordings).

Of course trying myself is the best, but just an idea for now as my budget limits me. Maybe in the future, i will permit myself to experiment more.
 
Peter Daniel said:
Pinkmouse is right.

Remember those swithes in older equipment ( called lodness)? The snubber does very similar thing. Did you ever see loudness switch on high end equipment?

I still use loudness in my ghetto blaster though ;)

Oh no :hot: now u really got me scared. I have an old technics amp with that button, and its only pressed in when listening to very electronic and basey music at lower levels (when base is a must), any other time, i cannot stand it for a second. :whazzat:
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.