Question: What kind of speakers are y'all using; what makes you think the Sure requires 24 to 30+ volts for this board? I find that 12V is plenty loud for my speakers, which are rated at 95dB/1m/1W. Or would a higher voltaic potential reap benefits other than mere sonic volume? Does the board not come into its own unless you're feeding it more than 12V? I suspect not, based on what I'm experiencing, but I know it's easy to be deluded by what you think is the high water mark.
Happy listening!
Exactly that. I find higher input voltage increases the dancability and chocolatiness of the output.
Finally got my board in today. Sounded horribly harsh and congested/constricted at first, so I just watched the Tyson documentary on DVD using the amp for audio. Got bored halfway through the video, so I put on the Kinsmen CD with Rudresh Mahanthappa (Indian-American jazz; won 2nd place in annual Village Voice jazz poll for 2008). Hmm, not as bad. Then played Tom Zé's 1990: Brazil Classics, Vol. 4: The Best of Tom Zé. This amp has some potential!
I'm hamstrung right now: I'm using a crummy Oppo DVD player, which was smoked the other night by a Creek CD player I gave to my girlfriend (she noticed the difference too, and I think feared I was going to try and reclaim said CD player).I'm also sending the signal straight from the Oppo to the amp, being preamp-less at the moment, though I'm fervently hoping that a Superphon Revelation Basic Dual Mono will soon wend its way to chez soldersmoker. Anyway, a few Dayton caps ought to really make this thing sing, and I'm not hating the naked board as Tom Zé does his weird instrumentation/syncopation thang.
Question: What kind of speakers are y'all using; what makes you think the Sure requires 24 to 30+ volts for this board? I find that 12V is plenty loud for my speakers, which are rated at 95dB/1m/1W. Or would a higher voltaic potential reap benefits other than mere sonic volume? Does the board not come into its own unless you're feeding it more than 12V? I suspect not, based on what I'm experiencing, but I know it's easy to be deluded by what you think is the high water mark.
Happy listening!
Fortunately we do not all have the same taste
. It sounds to me like the amp is revealing the poor quality of the recording on some of your material. I for one now detest watching divx rips with compressed audio for the same reason.Which Oppo player do you own?
I think you're question is self-explanatory? With 95dB speakers you of course do not need much power to make them sing and 12v is enough for the amp. People with proac clones etc. lingering around 80-85dB sensitivity need the extra power a higher rail voltage provides.
Question: What kind of speakers are y'all using; what makes you think the Sure requires 24 to 30+ volts for this board? I find that 12V is plenty loud for my speakers, which are rated at 95dB/1m/1W. Or would a higher voltaic potential reap benefits other than mere sonic volume? Does the board not come into its own unless you're feeding it more than 12V? I suspect not, based on what I'm experiencing, but I know it's easy to be deluded by what you think is the high water mark.
Happy listening!
Most people who have tried different voltages say that the amp is more musical and has more dynamics at higher voltages. I know the feedback resistors on the Sure are set for 32V so that might be the sweet spot. I'm using 34V on my mains and 36V on my sub. Can't say I hear much difference between them. Both sound good to me.
My speakers are diy open baffles at about 91dB efficiency. I don't know the efficiency of my open baffle sub. I run it 3dB hotter into the more powerful amp to get a flat response, so I'm guessing it is about 86dB or so.
-dr_vega
Hi all
I've just ordered a Sure 2 * 100 and want to get the power supply built while it arrives. Apologies for cross posting this from the power supplies forum but the couple of responses I got suggest that class D isn't really of interest to people on that forum. My question may still be stupid but here goes:
I've got a nice 300VA 24V toroidal transformer but don't know whether to regulate the output with a pair of LM338Ks or just smooth it.
Basic circuit is full wave rectification; thermistor surge protection; 0.1ohm, 2 * 22000uF capacitor RC smoothing,
Then the question is whether to regulate the output using the LM338s or just put another big capacitor after the RC filter. The LM338s would be set to give the highest voltage possible given their dropout characteristics.
What are the pros and cons?
Thanks
Peter
I've just ordered a Sure 2 * 100 and want to get the power supply built while it arrives. Apologies for cross posting this from the power supplies forum but the couple of responses I got suggest that class D isn't really of interest to people on that forum. My question may still be stupid but here goes:
I've got a nice 300VA 24V toroidal transformer but don't know whether to regulate the output with a pair of LM338Ks or just smooth it.
Basic circuit is full wave rectification; thermistor surge protection; 0.1ohm, 2 * 22000uF capacitor RC smoothing,
Then the question is whether to regulate the output using the LM338s or just put another big capacitor after the RC filter. The LM338s would be set to give the highest voltage possible given their dropout characteristics.
What are the pros and cons?
Thanks
Peter
Havoc08, it's a 981-HD. It doesn't sound that bad right now. I can't listen to compressed stuff, either. There's an ethereal presence to some Bach I'm listening to right this minute, and it's a pleasure for Sure. That said, I know a cheap CD player and a DAC are in my future. One weird thing I'm hearing now is a slight "pfft" between tracks, something like a stylus first touching a record, though of a shorter duration. It's not like my other amp was so cloaked that it couldn't reveal that sound, or . . . ? Damn DVD player!
dr_vega and ElFishi, I won't rest until I double the voltage. I gotta know for myself. I'll post impressions once I have a decent preamp in a couple of weeks. You would think 12 versus 24 volts would be definitive enough to draw a strong conclusion.
Can anybody suggest a decent transport? I'm probably going to get the Valab NOS DAC. Why did I ever get rid of my CAL?
dr_vega and ElFishi, I won't rest until I double the voltage. I gotta know for myself. I'll post impressions once I have a decent preamp in a couple of weeks. You would think 12 versus 24 volts would be definitive enough to draw a strong conclusion.
Can anybody suggest a decent transport? I'm probably going to get the Valab NOS DAC. Why did I ever get rid of my CAL?
@ soldersmoker
Ahh okay. I am considering the Oppo BDP-83 so was a bit concerned about your comments on the quality.
Actually some guys on the 41hz forum reports that amps like amp 9 sound better at 12v than 24v... go figure. Guess there is no way than to test it yourself with your ears and your equipment.
Regarding transport have you read the shigaclone thread?
Ahh okay. I am considering the Oppo BDP-83 so was a bit concerned about your comments on the quality.
Actually some guys on the 41hz forum reports that amps like amp 9 sound better at 12v than 24v... go figure
. Guess there is no way than to test it yourself with your ears and your equipment.Regarding transport have you read the shigaclone thread?
@ soldersmoker
Ahh okay. I am considering the Oppo BDP-83 so was a bit concerned about your comments on the quality.
Actually some guys on the 41hz forum reports that amps like amp 9 sound better at 12v than 24v... go figure
Regarding transport have you read the shigaclone thread?
The Oppo blueray player is supposedly a much better audio player than my DVD player. I'm very pleased with the Oppo for video use, especially for the bargain price. I'm sure you'll be happy with the '83.
I hadn't considered the shigaclone. That's a great idea! Thanks!
Especially as it can be made for $150 depending on how cheap you find the boom box
. I'm going to couple it with the cs4397 dac mentioned on this forum also and a T-amp, hopefully a killer combo I hope the oppo plays audio better than my trusty panasonic (old thing from way back when they still made quality, it's full of paasonic purism caps, os-cons etc.).
regulator
I had preferred a regulator in front of the smoothing in the power supply of my class AB amps based on the sound even though I was throwing away 4v but for some reason when powering up the Sure 2X100 the surge was so great that it put the positive regulator into current limiting and never would go beyond 7v. I had to remove the regulators and just use the big smoothing caps as most amps do. Then I bought the Meanwell 350W switch mode supply and it is night and day better sounding. I have also auditioned the analog supply with a CLC but found that it sounded better without the inductor. To me, all of the trials of diodes, inductors, and caps are moot now as the smps, like the class D amps as well, sound much quicker and more powerful than their analog counterparts.
Now if Meanwell would produce split rail supplies in a more cube type of form factor I would be very happy.
Terry
Very interesting and convincing argument in favor of a big switching PS. I'm unsure what you're saying about swapping components though. You would dispense with swapping out the input caps, for example? Do you feel doing so is a waste of time with no major sonic gains to be had once the big Meanwell is in place? Curiouser and curiouser.
Hi Guys,
Hit the send key and the sites down.
Start again. Here is my build of the Sure 4*100 board in a Carver M400 chassis. I bought two of these off ebay as not working. They certainly were not working but at the price they were cheap enclosures.
This build was for my computer desk and I incorporated a desk light with two 10W LEDs at 500 Lumens each.
Terry
Hit the send key and the sites down.
Start again. Here is my build of the Sure 4*100 board in a Carver M400 chassis. I bought two of these off ebay as not working. They certainly were not working but at the price they were cheap enclosures.
This build was for my computer desk and I incorporated a desk light with two 10W LEDs at 500 Lumens each.
Terry
Attachments
Still needs mods
I was referring to the work I had done with my analog power supplies over the years. As good as I could make it, the switching supply sounds much better. All of the evaluations of the the mods to the Sure 2X100 board were done with the smps providing the power. It still needs the mods.
As mentioned you still have to do the mods, but the PSU section can be cheapened. There is not much need in adding tons of bulk uF on the power input as the SMPS already contains a large amount of caps.
I'm sure however that substituting the SMD caps that power the chip with good quality os-cons or similar ESR would improve things. I changed the std caps on the ta2024 sibling with u-low esr caps and heard great improvement in dynamics and in background noise (for some reason.. maybe the std caps are just too poor quality).
Thanks. I don't know if Sure read this but if they do they should consider putting a fan on the 4*100 as they do for the 2*100 and have a small nice enclosure made that is perhaps a bit different. It is sort of nice being able to have a nice tiny amp that can run from a meanwell supply as well as a car battery, just the thing for a party where there is no power. The form factor is great.
Incidently, I am running the 12V fan on 8V. Can't hear it at all.
Terry
Sure...
Here they are...
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Duc
It seems to me that D class amps require shielded input wire. A good triple shield in fact.
Terry
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