Hi Lars,
The new 700XE looks great, I can't wait to see the measurements.
After swapping over to the zap 2.3SE's from my previous UcD400's, I haven't felt the need to go back. The dynamics, soundstage and imaging with the zaps is simply amazing!
If the 700XE is meant to deliver all these great attributes, with the bonus of more detail and less noise, then I am certainly going to get my hands on a couple.
Bring it on!!!
The new 700XE looks great, I can't wait to see the measurements.
After swapping over to the zap 2.3SE's from my previous UcD400's, I haven't felt the need to go back. The dynamics, soundstage and imaging with the zaps is simply amazing!
If the 700XE is meant to deliver all these great attributes, with the bonus of more detail and less noise, then I am certainly going to get my hands on a couple.
Bring it on!!!
whams said:Hi Lars,
The new 700XE looks great, I can't wait to see the measurements.
After swapping over to the zap 2.3SE's from my previous UcD400's, I haven't felt the need to go back. The dynamics, soundstage and imaging with the zaps is simply amazing!
If the 700XE is meant to deliver all these great attributes, with the bonus of more detail and less noise, then I am certainly going to get my hands on a couple.
Bring it on!!!
Hi whams
How much better, do you think, that the zap2.3SE's are to your previous UcD400's? 😱
The new zap700XE looks really great, doesn't it.
🙂 I previously asked Lars these questions;
Hi Lars: It sounds like the 700XE has completely resolved the midrange leanness/edginess that the 2.3SE can have. Is that correct?
It also sounds like the 700XE has dramatically better detail and focus. Is that correct?
Lars' reply was;
Yes exactly! Both questions...
Exciting isn't it? We can expect the midrange, detail and focus, with the zap700XE to be dramatically better than the current zap2.3SE. What do you think, cool or what? 😎
Bring it on, alright!!!
😀Lars Clausen said:
So its quite a change from the 2.* models. (not completely plug and play in all cases, because of the extra 40 mm. Of course when you start from scratch this is not an issue. Size matters 😉 )
The 3 potmeters are for finetuning by LCaudio, I guess. How stable is this fine tuning? Will re-adjustments after some time be required?
Still I am seriously thinking about the upgrade path. Its a nice option for early customers.
hello,
here some photos about my amp
It is not finished, i must do the treatment: anodization .
Seb
here some photos about my amp
It is not finished, i must do the treatment: anodization .
Seb
Re: Wow...
Thank you 😉
It take me 25 hours to do it . I will put another pictures tomorrow.
Seb
Cobra2 said:
Thank you 😉
It take me 25 hours to do it . I will put another pictures tomorrow.
Seb
Hi Folks,
T-networks from Lars have just played at a low volume for only about five minutes. They haven't begun to break in, but almost seems like they don't even need to. Initial impression, stunning. Is there a difference? I found the Cerafines had a real smooth and pleasing sound, while the T-networks have crystal detail. Hell yes there's a difference. Personally I prefer the crystal detail. I'll see how they deliver tomorrow once I've run them in, keep you posted.
Oh yeah, no reforming even considered, the ol caps in stock are just fine!
My sincere thanks Lars.
Chris
T-networks from Lars have just played at a low volume for only about five minutes. They haven't begun to break in, but almost seems like they don't even need to. Initial impression, stunning. Is there a difference? I found the Cerafines had a real smooth and pleasing sound, while the T-networks have crystal detail. Hell yes there's a difference. Personally I prefer the crystal detail. I'll see how they deliver tomorrow once I've run them in, keep you posted.
Oh yeah, no reforming even considered, the ol caps in stock are just fine!
My sincere thanks Lars.
Chris
classd4sure said:
Hi classd4sure
You have finally added them to your PS? 🙂 Yes, Lars T-network caps are terrific.
They are very fast (and as you say have crystal detail), but, because they are so revealing you need to control the bridge zener noise, with an array of 220nF PPcaps (around the bridge). 
Chris, what is reforming?
KLe said:
Hi classd4sure
You have finally added them to your PS?Yes, Lars T-network caps are terrific.
Chris, what is reforming?
I have and I love them. Though I have to admit due to prior experimentation my results aren't so meaningful, as I also changed a few other components at the same time, like the step up from a cheap 26 amp bridge rectifier to dual 68 amp 600V FRED rectifiers from IXYS.
Then again, the argument is made that you have to use the T-networks properly to get the most out of them. That warrants the change over to the dual rectifiers, and yeah it's alot better. If you just wire them like a normal cap they probably won't sound any different.
The power I get out of it now is just unreal, and it stays crystal clear and neutral alllll the way from very low volume to the point my vision blurrs.
I really wish I had more to use in my final amp because 10 000uF per rail isn't enough for a stereo amp @ 4ohm load.
I picked up some Jensen 4 poles, 15 000uF 63V, will have 2 per rail. I don't know if they're slit foil as well though? Let you know how I like those against the BHC T-networks real soon.
Incidentally I do eventually plan on bypassing the rectifier bridges with say 100nF, but since they're FRED diodes in an eco pack, it doesn't seem to be a requirement.
Reforming...... hmm..... well..
http://www.nmr.mgh.harvard.edu/~reese/electrolytics/
I've never done it, don't want to, but it's an option available if shelf life has been exceeded for your caps and they've degraded. I figure shelf life is a very conservative rating and just opt to plug it in and see what smokes, expecting none, of course.
I think I prefer the method where you limite the charging current to their rated leakage current.
Anyway, caps are excellent, their shelf life hasnt' ruined them, totally worth it.
Let you know what I think of the Jensen caps.
Cheers,
Chris
classd4sure said:
Hi classd4sure
dual 68 amp 600V FRED rectifiers from IXYS
... WOW 68 amps! I do not know these rectifiers but do they have certain qualities that you consider special?From my experience with BHC T-network caps, if you just wire them like a normal cap they probably won't sound as good, because, they will reveal the PSU noise.
I haven't been game to try paralleling the BHC T-network caps, as yet ... afraid of them smoking or at worst, exploding?
I believe, educated guess, that paralleling them should remove the need for PS snubberizing, because the PS will have a lower output impedance. Chris, yes please, keep us informed of how paralleling the Jensen 4 pole caps, goes?
KLe said:
Hi classd4sure
dual 68 amp 600V FRED rectifiers from IXYS
From my experience with BHC T-network caps, if you just wire them like a normal cap they probably won't sound as good, because, they will reveal the PSU noise.
I haven't been game to try paralleling the BHC T-network caps, as yet ... afraid of them smoking or at worst, exploding?
Chris, yes please, keep us informed of how paralleling the Jensen 4 pole caps, goes?
This is them:
http://www.ixys.com/l363.pdf
Special.... noooo
If you look around on this forum, solide state section, you'll find extensive discussions about it.
FRED rectifiers to mean = Ultra Fast Soft Recover.
That means you get a very low Trr, along with a very low IRM, so very little EMI is generated, low noise, clean switch. So clean some would say you don't need to bypass them, others would say you should anyway (which I agree with).
Better would be schottky rectifiers, considered to have no reverse recovery time, and so no reverse recovery current, but circuit parasitics would still give it some kick/resonance, and they should be snubbed with RC networks to prevent it. They also have the lower forward drop if you select them right.
The problem with schottky's is I don't see any in something like an eco pack. I had considered 68amp schottky dual rectifiers in iso-top I think? But had decided not to go that way for two reasons. They'd have taken up alot more real estate in my case, and the need to wire them p2p was likely to pick up more noise than they would have cured.
There's one last special feature of my FRED bridges... 68 amps continuous! Bring on the welding rods.
Want to hear something funny? At mid volume with the old setup (a single ~26 amp bridge rectifier) my 500VA would get warm. With this rectifier setup, I couldnt' get it to heat at all.
The Jensen 4 pole app notes give you alot more info on how to parallel them. I'll be going by them, but yeah, it's confusing isn't it? I quad guessed myself just wiring two and it's a good thing I did too.
Regards,
Chris
classd4sure said:
Hi Chris
i felt the same effect from Cerafine to Sikorel which are very fast
rather than paralleling PSU caps , i noticed that pi filtering is VERY effiscient ( on my UCD180 ) :
sikorel + aircore inductor 4mH Rs=0.5 + sikorel
with them , it ' s not the same amp !
Alain
rha61,
By pi filter,
Do you mean cap - choke (4mH) - cap?
Have you tried replacing the choke with a small resistor?
By pi filter,
Do you mean cap - choke (4mH) - cap?
Have you tried replacing the choke with a small resistor?
rha61 said:
Salut Alain!
I'm simply paralleling to attain enough charge reserve to power some hungry (dual ported) 400W 4ohm speakers, lowering parasitics of these great caps wasn't on my mind, just an additional benefit.
If they were 8 ohms I wouldn't bother, and maybe after I've done it, I'll want to go back to just two, because it's not bad at all now, though I know there's more bass hiding in there somewhere.
Excellent tip on the PI filter, thank you. Do you do your snubbing in addition to this as well?
Your amp must have some great sound I think 🙂
I'd have to do more research/simulation/number crunching
about PI filters with T networks before attempting that.Or just convince someone else to try it first 🙂
Regards,
Chris
zap amps
Is it possible to get a schematic for the zap amps to see how pwm can be done,I was thinking of using tl494 or sg3524 as a easy way to build a class d amp
Is it possible to get a schematic for the zap amps to see how pwm can be done,I was thinking of using tl494 or sg3524 as a easy way to build a class d amp
ackcheng said:
yes i mean cap-choke-cap on each rail
i've tried a 0.5R after the choke to obtain 1R
classd4sure said:
Salut Alain!
I'm simply paralleling to attain enough charge reserve to power some hungry (dual ported) 400W 4ohm speakers, lowering parasitics of these great caps wasn't on my mind, just an additional benefit.
If they were 8 ohms I wouldn't bother, and maybe after I've done it, I'll want to go back to just two, because it's not bad at all now, though I know there's more bass hiding in there somewhere.
Excellent tip on the PI filter, thank you. Do you do your snubbing in addition to this as well?
Your amp must have some great sound I think 🙂
I'd have to do more research/simulation/number crunching
Or just convince someone else to try it first 🙂
Regards,
Chris
no snubber anymore
in my case the pi filter is more beneficial than the snubber and i've not tried them together
i'm still amazed by the natural sound we can get from these little modules 😎
Alain
Re: zap amps
That's a commercial product which is in production, I wouldn't even bother asking for a schematic.
steven344 said:
That's a commercial product which is in production, I wouldn't even bother asking for a schematic.
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