$175 Class D amp--120 wpc

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wgscott

Re: $175 Class D amp--120 wpc
« Reply #2660 on: 19 Jun 2011, 06:55 am »
No, it really is just the amp.  This happens even when everything else is off.

TrungT

Re: $175 Class D amp--120 wpc
« Reply #2661 on: 19 Jun 2011, 07:48 am »
Please more detail when it pop.

guest1632

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Re: $175 Class D amp--120 wpc
« Reply #2662 on: 19 Jun 2011, 08:30 am »
I just bought 2.2 k Vichay naked resistors but haven't had a chance to stick them in yet.

So what you waiting for? All ears want to know how it sounds.

Also, I had asked this question I think before, and didn't receive an answer. So I'll try again.

Would I get better sound if I used say two SDS224 each bridged versus one SDS25? Any help would be most appreciated.

Ray Bronk4

wgscott

Re: $175 Class D amp--120 wpc
« Reply #2663 on: 19 Jun 2011, 01:37 pm »
Please more detail when it pop.

If everything is powered down, and I turn on the AC power to the transformer and power supply that feeds the two SDS 254 amp boards, I hear 2 pops in rapid succession.  If I have one amp board connected, I hear a single pop.  They aren't loud or anything terrible, and it definitely is not a thump, but just slightly annoying.  The amp turns off silently.

wgscott

Re: $175 Class D amp--120 wpc
« Reply #2664 on: 19 Jun 2011, 01:40 pm »
I just bought 2.2 k Vichay naked resistors but haven't had a chance to stick them in yet.

So what you waiting for? All ears want to know how it sounds.

Time. 

Also, I had asked this question I think before, and didn't receive an answer. So I'll try again.

Would I get better sound if I used say two SDS224 each bridged versus one SDS25? Any help would be most appreciated.

Ray Bronk4

Why not use two SDS 224 (or 254) vertical bi-amped?

wgscott

FrontPanelExpess promo code
« Reply #2665 on: 21 Jun 2011, 05:38 pm »
I used Front Panel Express to make my front and back plates.  It wasn't cheap, but the quality was outstanding. 

I have a promo code for $20 off  (min $100 order) before the end of August 2011.  PM me if you can use it.

I also have an image for making the Class D Audio color engraved logo, if anyone wants it.  It was a PITA to generate, so please feel free.  As it is a vector graphic, it scales up or down.


wgscott

Re: $175 Class D amp--120 wpc
« Reply #2666 on: 22 Jun 2011, 12:15 am »
Well, I finally managed to put in my four Vishay VAR-Series "naked" Z201 Z-FOIL RESISTORS.  I don't know the audiophool terminology, but piano (first think I have listened to) somehow sounds more realistic.  They certainly in no way made anything worse. 

I bought some new molex connectors so I could keep the pots ready to swap back in, but unless I need to experiment more with gain if I active bi-amp, I doubt I will be doing that.  My crimping skills are better than my soldering skills, and my heat sink isn't confidence-inspiring. 

Anyway, if you don't need the pots, these are a great replacement ($15 ea.).

toxteth ogrady

Re: $175 Class D amp--120 wpc
« Reply #2667 on: 1 Jul 2011, 06:25 pm »
It's been a while since I've posted to this thread, or to Audiocircle for that matter. Reading up on some of the comments I was surprised to see a few people dissatisfied with their amplifiers. What I've come to learn over the last year is that these amplifiers sound 'good' in basic kit form. But when the power supply is upgraded along with fixed resistors in place of the gain pots and careful matching of components (impedance) the sound truly does rival higher end amplifiers.

I own a sds-258 with upgraded Jensen 4-pole power supply using Uriah Dailey's Lighter Note LDR based volume control and sometimes the hotrodded Salas DCB1 buffer (depends on the music.) It's a terrific FULL RANGE combo driving my Ohm Walsh 5000 speakers and continually has me shaking my head in disbelief at the level of sound quality achieved with a little DIY. Prior to my sds-258 amplifier I owned an Accuphase E-450 so I'm not kidding when I say these amplifiers have potential. I really have no intention of changing anything in my system because it's the best I've heard it in a long time, although I still am curious to hear how a simple yet excellent tube preamp would jive with everything. I know a lot of you are happy with the Dodd buffer but curious to see if anyone has tried the Decware CSP2 with their ClassDaudio amplifier. Anyone?

corndog71

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Re: $175 Class D amp--120 wpc
« Reply #2668 on: 1 Jul 2011, 09:17 pm »
I still recommend the Bottlehead Quickie with PJCCS upgrade.  For around $150 including shipping it's a sweet little preamp. 




wgscott

Re: $175 Class D amp--120 wpc
« Reply #2669 on: 1 Jul 2011, 09:49 pm »
Sorry to be lazy, but do you have a Bottlehead link?

srb

Re: $175 Class D amp--120 wpc
« Reply #2670 on: 1 Jul 2011, 10:10 pm »
I still recommend the Bottlehead Quickie with PJCCS upgrade.  For around $150 including shipping it's a sweet little preamp. 

If you run it for 4 hours a day, that's 40 9-volt and 20 D-cell batteries to the landfill each and every year.  If you use rechargeables, there aren't many chargers that will charge that assortment of batteries simultaneously.
 
For me, I just can't see it being worth the hassle and/or the waste.
 
Steve
« Last Edit: 2 Jul 2011, 02:10 am by srb »

jeffh

Re: $175 Class D amp--120 wpc
« Reply #2671 on: 1 Jul 2011, 11:35 pm »
Sorry to be lazy, but do you have a Bottlehead link?

http://www.bottlehead.com/


raindance

Re: $175 Class D amp--120 wpc
« Reply #2672 on: 2 Jul 2011, 01:58 am »
I haven't posted for ages due to losing interest after I got my SDS-254 amp. Now I'm back. I still maintain that the CDA-254 is the better sounding amp by a long shot (for my ears at least) due to a black background (very very low noise floor). But the reason I'm posting - I just resurrected my CDA-254 amp to try with my Little Dot Mk III headphone amp (as a preamp). It has a 600 ohm output impedance, so it matches the CDA series amp really well.

Well, match made in heaven. The low gain of the CDA amp suits the highish gain I'm running the Little Dot at perfectly (this is another subject, but the higher gain settings use less feedback on the Little Dot). Absolutely wonderful pairing, really blew me away. Anyone else try this?

wgscott

Re: $175 Class D amp--120 wpc
« Reply #2673 on: 2 Jul 2011, 04:01 am »
http://www.bottlehead.com/
:oops:  :duh:

These people do not appear to be as easily distracted as I would have been:

corndog71

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Re: $175 Class D amp--120 wpc
« Reply #2674 on: 2 Jul 2011, 06:13 am »

If you run it for 4 hours a day, that's 40 9-volt and 20 D-cell batteries to the landfill each and every year.  If you use rechargeables, there aren't many chargers that will charge that assortment of batteries simultaneously.
 
For me, I just can't see it being worth the hassle and/or the waste.
 
Steve

Well, that's not even considering its sonic qualities which are pretty damn good for the money.  And really, the batteries seem to last longer than you'd think.

praedet

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Re: $175 Class D amp--120 wpc
« Reply #2675 on: 2 Jul 2011, 12:20 pm »
So, are they in parallel somehow, or series?  What voltage does it actually need?

corndog71

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Re: $175 Class D amp--120 wpc
« Reply #2676 on: 2 Jul 2011, 03:58 pm »
The tubes are 3S4.  The D cells heat up the filaments.  One for each tube.  The 9V are run in series to get 36V for the "high" voltage.  The PJCCS helps tighten things up electrically which ends up as improved detail, bass, and just a better over all sound.  It's a very simple circuit.  I suppose you could save some money buying 3 big AGM batteries and hooking them up in series to get 36V.  You would have to take them out of the circuit and switch to parallel in order to charge them.  You probably would need to charge them once a year if that.   :wink:

Of course if you want a truly superior tube preamp the Foreplay 3 is also available.

srb

Re: $175 Class D amp--120 wpc
« Reply #2677 on: 2 Jul 2011, 04:07 pm »
If you run it for 4 hours a day, that's 40 9-volt and 20 D-cell batteries to the landfill each and every year.  If you use rechargeables, there aren't many chargers that will charge that assortment of batteries simultaneously.

Well, that's not even considering its sonic qualities which are pretty damn good for the money.  And really, the batteries seem to last longer than you'd think.

It's not "what I think", my calculations of the number of batteries you would toss away were based on the manufacturer's estimate of 100-200 hours as well as actual user measurements of 100mA draw from the the two parallel D-cell batteries for the filament circuit and 4mA draw from the four series 9V batteries for the plate circuit.
 
I used 150 hours for calculations, so not even the worst case scenario.  I don't doubt the sonic qualities for the money, just as I don't doubt the sonic qualities of the Sutherland Ph.D. phono preamp with it's 16 D-cells.
 
Again, for me, these multiple battery power schemes are just too far beyond the somewhat less wasteful or less hassle to remove, charge and replace multiple rechargeable batteries than components that use single LA, AGM or LiFePO4 batteries with permanently connected smart chargers.  YMMV.
 
Steve

Letitroll98

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Re: $175 Class D amp--120 wpc
« Reply #2678 on: 2 Jul 2011, 04:57 pm »
Apparently neither do the posters on this thread, nary a comment.  They are a single minded lot, don't you think?  Do you suppose she might show up at the Capital Audio Fest next week?  I wonder if those legs go all the way up?  I'm going to take a cold shower now.   

:oops:  :duh:

These people do not appear to be as easily distracted as I would have been:


Steidl Guitars

Re: $175 Class D amp--120 wpc
« Reply #2679 on: 2 Jul 2011, 06:19 pm »
These people do not appear to be as easily distracted as I would have been:

Well, you've seen one reel to reel, you've seen them all.

 :wink: