amps and SDA's

I am by NO MEANS an authority on the subject but, it's pretty much agreed that bridging messes up the bass and gives loosey goosey damping. The other matter (at least with Carvers) is that anything less than 8ohms for load, is really asking for trouble with the amp in bridged mode. Lots of threads/posts on this over at CarverAudio.com- Just tried a search over there and the search feature is down right now, if you post your question I'm sure OBI56 will give you a detailed answer.:)

http://www.carveraudio.com/phpBB3/index.php

you guys and your watts.......30wpc here with 1C's and doing better than ever!!! Bridging is not recommended for a variety of reasons already mentioned.

Yes, I can sympathize with "watt chasers" as sometimes room dimensions (very large listening rooms) can benefit.............but I always look at other things like topology, design, components, etc.

I'll concede that with my 30wpc I won't win a pure SPL competition, but my single ended pure class A 30 watts sound better than anything I've auditioned in a long time. If I move to a very large listening area I'd have to get a bit more juice for louder listening.

My current amp has twice the filter capacitance of my old 125wpc amp and is more dynamic in every way. I have no trouble sitting 6 feet away and hitting 95dB and the amp isn't even straining at that point.

Just throwing it out there as an example of watts and specs don't mean a whole lot..........or are merely a small part of the entire picture.

I wouldn't bridge the amps in this scenario as the added watts aren't worth the sacrafice in sound quality and I'm pretty sure the Carver's won't like the impedance of the 1C's when bridged (not many amps do).

YMMV

H9

heiney9 wrote: »

Yes, I can sympathize with "watt chasers" as sometimes room dimensions (very large listening rooms) can benefit.............but I always look at other things like topology, design, components, etc.

I'll concede that with my 30wpc I won't win a pure SPL competition, but my single ended pure class A 30 watts sound better than anything I've auditioned in a long time. If I move to a very large listening area I'd have to get a bit more juice for louder listening.

My current amp has twice the filter capacitance of my old 125wpc amp and is more dynamic in every way. I have no trouble sitting 6 feet away and hitting 95dB and the amp isn't even straining at that point.

Just throwing it out there as an example of watts and specs don't mean a whole lot..........or are merely a small part of the entire picture.

I wouldn't bridge the amps in this scenario as the added watts aren't worth the sacrafice in sound quality and I'm pretty sure the Carver's won't like the impedance of the 1C's when bridged (not many amps do).

YMMV

H9

H9, what kind of AMP are your running ? Probably was mis-guided when I bought my Carver TFM-45. It does sound great but I am curious how it might stack up againest a lower wpc AMP.

No disingenuous intent here just trying to learn.

I've found having a lot of headroom (way more than the speaker can handle) makes a HUGE difference on sudden, short transients (snare drum pop, piano strikes,, etc.), regardless of volume level.

To the OP, if you decide to go against the norm and bridge your amps be aware not all SDA's can use the AI-1 cable. Only the later generation SDA's are capable. What model SDA's do you have? if they can't run the AI-1 cable.................this becomes a moot point.

H9

heiney9 wrote: »

Pass Labs Aleph 30 is what I'm running. I have no doubt the Carver is a nice capable amp that many here own and are happy with. I was simply commenting (in general) with people wanting to "bridge" their amp to go from 250 wpc to 400 wpc or whatever higher output, etc., etc., etc.

Really is a non-issue............in most cases bridging combines the (2) halves of a stereo amp and there is usually a degredation of sound plus the amp now see's a lower impedance which means they struggle to run anything below 8 ohms.

I don't recommend bridging except in some rare cases of amps; ie; Monarchy SM70's. When you bridge those they become a single ended balanced circuit and are designed to be run that way. Or in the case of bridging a single amp to run a sub which is 8 ohms or greater.

Hope this hepls

H9

Thanks H9, Pretty interesting reading the manual for your Pass Labs Aleph 30.

Looks like a hard AMP to get your hands on. Someday, maybe someday.

That's very true....not imagined. Most tube amps (lower power) have very simple gain paths 2 or 3 stages only and superb linearity. Same with many singled ended class A topoligies (like many of the Pass Labs offereings; including the Aleph w/ only 2 gain stages).

A simple path from input to output with premium parts seems to do a great job and achieves excellent linerarity (which is extremely important) vs. a mediocre push/pull A/B topology which can have anywhere from 5-7 or more gain stages and a large amount of negative feedback to control linearity which adds 3rd order harmonic distortion which can be very unpleaseant.

H9

All correct Zingo.............my comments are based on the difference's I've heard in my system with my SDA 1C's w/my new amp compared to a few other 3-4 times the wattage amps. There are no hard and fast rules and everything you stated applies.

Like I stated earlier if I moved into a much larger room and expected higher SPL, then I would need more watts to fill upthe space at whatever higher SPL I wanted to listen at.

I posted this yesterday in another thread......sort of applies here as well, but it's still a general statement about "output" and not quality.

We've all used the term "decibel" hundreds of times, but what does it REALLY mean? A decibel (named for Alexander Graham Bell) is a tenth of a bel, and is used as an expression of power. Here's where the confusion arises: A decibel isn't a measure of ANYTHING; it is a ratio of two power levels. Because of the way our ears perceive volume, these ratios follow a logarithmic curve, expressing them as a decibel keeps things easier to deal with. Here are a few convenient decibel figures worth remembering: One decibel is commonly taken as the smallest volume change the human ear can reasonably detect. Doubling the POWER of an amplifier results in a 3 dB increase, which is a "noticeable" volume increase. Doubling the VOLUME of a sound is a 6 dB increase (you may occasionally see 10 dB listed as the "double-volume" figure, 6 dB is the more mathematically correct number). By doing the math, you can see that truly doubling your volume actually requires 4 times the amplifier power! Keep these figures in mind the next time you are comparing the specs of two pieces of equipment...

The only experience that I've ever had with bridging was with a pair of Adcom 555's,, tried it once and never again, with a pair of 11T's. I was driving my 1C's with a 40 watt tube amp,, and it was plenty.Good luck.

IMO TFM-45 or 55

I have two tfm 24's going to my 3.1tl's.You can horizontally or vertically bi amp them but if your speakers go below 8 ohms you can not switch the carvers to mono and bridge them.This came straight from Rita a couple of years ago.

Correct

TUBES and 1C's go together like Peas and Carrots;)

davidfmartin wrote: »

I don't have the equipment to benchmark the wpc but with a 400va transformer my guess would be around 40-50wpc based on the specs.

Depending on rail voltages,with +-36 volts I measured about 40 watts before severe clipping on the unit I built. http://www.polkaudio.com/forums/showthread.php?t=71781&highlight=GAINCLONE+MAKEOVER