No joke? Wow, I'll try that TODAY and tell you what it sounds like!
It does make sense...
I have not tried this, but I plan to... Remember the source and amp have to use decoupled power supplies, otherwise you'll have +2.5v of DC going to the amps inputs - not a good thing!
I'm hoping to try the meanwell with no earth connection, if it works ok, then it should be decoupled from my DCX, and I should be able to do away with the input cap.
You can also use input transformers, which is a nice way of going capless.
Thanks, once I've found out what impedance I need then I'll order some, I'll be more than happy if they turn out to be better than the Alps blue.
I guess being stepped they'll have less gang error too.
You mean the upstream kit (the preamp connecting to your Charlize amp) has output caps, so you would not need the caps in the input of your amp.
Most of my amps have no input cap, as my tube based preamp I use have DC blocking caps on thier output.
I agree, the most expensive caps sound worse than no cap at all. Unless your interested in aquiring a certain sound.
Hi john65b, yes upstream (duh!) I meant.
I use a yaquin cd1 tube buffer with Teflon ft-3 output caps 2x 0.47 parallel per channel so just under 1uf per channel to my Charlize2 with no problems and no bass rolloff. As my TK250 is still in transit, so cant try it myself yet, I was wondering why nobody has yet tried it without input caps. I see people opting for 2.2uf, which must be for other reasons other then bass rolloff as I dont have that with 1.0uf.
Have you tried it yourself without input caps, as you do with your other amps john65b?
I use a yaquin cd1 tube buffer with Teflon ft-3 output caps 2x 0.47 parallel per channel so just under 1uf per channel to my Charlize2 with no problems and no bass rolloff. As my TK250 is still in transit, so cant try it myself yet, I was wondering why nobody has yet tried it without input caps. I see people opting for 2.2uf, which must be for other reasons other then bass rolloff as I dont have that with 1.0uf.
Have you tried it yourself without input caps, as you do with your other amps john65b?
gripracer: I can't believe I didn't think of this before, but you may be able to do away with your input cap...
I'm assuming you do not charge your batteries when using the amp? If so, this means your power source is floating (not earthed) meaning you won't need an input cap. I'm not 100% sure on this however, so hopefully someone else can confirm if I'm right about this.
I plan to run one of these boards from li-ion batteries, and another from a SMPS, and I plan to do away with the input cap on the battery powered board...
I'll be interested to hear your opinion on how it compared to the TKD...
I'm assuming you do not charge your batteries when using the amp? If so, this means your power source is floating (not earthed) meaning you won't need an input cap. I'm not 100% sure on this however, so hopefully someone else can confirm if I'm right about this.
I plan to run one of these boards from li-ion batteries, and another from a SMPS, and I plan to do away with the input cap on the battery powered board...
No problem, I'll be ordering a few myself once I'm 100% sure on what values I'm going to use.
I'll be interested to hear your opinion on how it compared to the TKD...Are you saying that using axial electrolytic capacitors in this, or any class D amp is a bad idea? What about radial lead capacitors?
Does this also apply to those who have already modded their own sure tk2050 amp and have replaced the whole output stage on a separate bread board?
Maybe someone else will want to chime in with their own thoughts/opinions on this.
Just do a Google search on "class D layout" and follow the first link. Here is the direct path: Circuit board layout guidelines for Class-D amplifiers | Audio DesignLine
Corroborates most of Eva's reply
you won't be disappointed, I promise.
Innnnnteresting....
But people with SMPS supplies don't send an earth from their power supply either? Both SMPS and Battery just use the + and - connection.
The Charlize2 is very fussy and wont share the ground with anything else. I use a battery during the day for critical listening. The charger circuit is completly isolated with a switch, and I charge over night. If I want to burn in speakers or caps etc, I switch to my SMPS for the wee hours. It is floating as well. So no issues there. So should be the same wit the sure board, if you use batteries or SMPS..... no input caps!
Well this depends on what SMPS you are using. On my meanwell supply, the - DC connection is connected to the mains earth pin, meaning the supply is not floating. I have yet to see if the meanwell works without an earth connection however, and I need to check if this is safe to do also.
Other SMPS' may give a floating output, often the brick types with only a 2 pin connector to the mains will give a floating output.
This needs to be checked BEFORE you bypass the input caps, otherwise you'll be sending a lot of DC to the speakers, and I doubt it will do the amp much good either, it's best to err on the side of caution here.
Brilliant, just what I wanted to hear, I think I'm going to try bypassing the input caps on my battery powered board when I get the chance.
+24V to 0V can mean +12V to -12V, voltage is relative. Where 0V is depends on how you connect.
Design has been slightly modified for better performance. 2x 2200uf Fine Gold has been changed to 6x 470uf MUSE KZ.
Complete list for those interested:
4x 10uh 3a coils from arjenhelder on ebay for output coils
4x .22uf 100v MKP2 from mouser for decoupling caps
4x .47uf 400v MKP10 from mouser output caps
6x 470uf 50v Nichicon UKZ from mouser for main power caps
2x 100uf 50v Nichicon UKW from mouser for the two little caps next to the little voltage regulator.
Complete list for those interested:
4x 10uh 3a coils from arjenhelder on ebay for output coils
4x .22uf 100v MKP2 from mouser for decoupling caps
4x .47uf 400v MKP10 from mouser output caps
6x 470uf 50v Nichicon UKZ from mouser for main power caps
2x 100uf 50v Nichicon UKW from mouser for the two little caps next to the little voltage regulator.
Hi Grip,
have some questions to you or another members here reading this thread:
1) Why you changed your first konfiguration ? Sound quality or techniqual reason ?
2) Is the 2 x 100 W board still available ? Couldnt find this version presently offered. I see only the 4 x 100 W Version of sureelectronic.
Thanks,
can you show me at least the ebay link where it´s offered ... ?
Obviously I am too stupid to find it.