RobWells said:
Damn that's a nice bit of kit.
And when they say dual mono they mean it
Passive cooling is a huge bonus too, actually its the thing that always meant I wouldn't buy a pro amp.I'd be up for one of these Al. Would make a nice sub amp one day and for £200... you can't really buy a decent mono plate amp for that.
5 pages
sdclc126,
I bought the amp from an older gentleman who now is retiring his gig. Not sure if it's still available online. It was made by a local company here in SoCal, but I guess they're not in business anymore.
I can hardly hear the fan in this amp though, it's extremely silent from 8' away.
I have some chip amp boards that has been sitting in the closet for the last year, never got the time to start building them. Now that I'm converted to pro amps, I don't think I'll even start the chipamp project at all. Not sure if it's worth the cost compare to the pro amps.
I may need to get another dcx2496 to run a full 4 way dipole setup. Anyone got one for sale?
sdclc126,
I bought the amp from an older gentleman who now is retiring his gig. Not sure if it's still available online. It was made by a local company here in SoCal, but I guess they're not in business anymore.
I can hardly hear the fan in this amp though, it's extremely silent from 8' away.
I have some chip amp boards that has been sitting in the closet for the last year, never got the time to start building them. Now that I'm converted to pro amps, I don't think I'll even start the chipamp project at all. Not sure if it's worth the cost compare to the pro amps.
I may need to get another dcx2496 to run a full 4 way dipole setup. Anyone got one for sale?
My amp 'expertise' extends no further than soldering a chip amp together so please excuse this question. Looking at the spec of the QSC 3800, I see the THD is quoted at 0.1%. Does that mean something like this amp ,with a quoted THD of 0.0035% will sound better (in theory)?
I appreciate that the 3800 has a lot of other features and. much more power.
I appreciate that the 3800 has a lot of other features and. much more power.
Nuuk, the THD for those two amps are specified in different ways. The BK one is a typical THD at a given 'not near clipping' power level. The QSC 0.1% is industry standard for measuring full power (they load up the amp then turn up the level until distortion reaches 0.1% then measure power) and the typical 'not near clipping' THD will be comparable to the BK THD.
I would argue that an for domestic amps with 0.1% vs 0.001% THD the lower THD one may not necessarily sound better, but with proper pro amps generally it's not an issue as the power supplies are so hefty they are almost out of the equation so yes as a generalisation the lower THD will be better.
Al, how old are those amps? There is a small chance I might be interested.
I would argue that an for domestic amps with 0.1% vs 0.001% THD the lower THD one may not necessarily sound better, but with proper pro amps generally it's not an issue as the power supplies are so hefty they are almost out of the equation so yes as a generalisation the lower THD will be better.
Al, how old are those amps? There is a small chance I might be interested.
I like BK Electricals. They produce good quality budget kit, and in theory you're right, lower distortion is better. But I look at those tiny traffos, small PSU caps, bent metal heatsinks...
The 3800 is a class G amp, and so will always have slightly more distortion than an equivalent AB amp. But for the majority of the time, even in pro use, it will be running on the lower rails, with no switching noise. With the QSC, you also have much more headroom, so transients won't be squashed, and the current delivery to drive those awkward drivers with strange impedance dips, this leading to a more synergystic system.
Oh, and I also trust the QSC specs more than I do the BK ones.
Regarding the amps, my mate was out on a job yesterday, I'm expecting a call back today.
edit: I'll find out for you Richie
The 3800 is a class G amp, and so will always have slightly more distortion than an equivalent AB amp. But for the majority of the time, even in pro use, it will be running on the lower rails, with no switching noise. With the QSC, you also have much more headroom, so transients won't be squashed, and the current delivery to drive those awkward drivers with strange impedance dips, this leading to a more synergystic system.
Oh, and I also trust the QSC specs more than I do the BK ones.
Regarding the amps, my mate was out on a job yesterday, I'm expecting a call back today.
edit: I'll find out for you Richie
Nuuk said:My amp 'expertise' extends no further than soldering a chip amp together so please excuse this question. Looking at the spec of the QSC 3800, I see the THD is quoted at 0.1%. Does that mean something like this amp ,with a quoted THD of 0.0035% will sound better (in theory)?
I appreciate that the 3800 has a lot of other features and. much more power.
Most manufacturers distortion specs are at 1w when your looking at 0.00X%. Its nice to know that at nearly 400w these are only reaching 0.1% the Hypex UcD400 is a low distortion design, yet has 1% distortion at 400w.
I guess my point is that most figures from different sources are rarely completely comparable. Those figures from QSC are honest and straight down the line.
Al, still wanting one of these can you keep me updated on prices and when/how you want payment etc.
Thanks for the replies guys.
As I am about to switch over to dipole woofers instead of my TL types, I am also wondering about driving them 'properly'. So I may be interested in one of the QSCs as well (I have a nuclear power station handy to power it up ).
Obviously age and condition come into the decision here as well. They look fairly complex to me with all those output devices. I wouldn't want to be faced with the cost of repairing one too soon.
As I am about to switch over to dipole woofers instead of my TL types, I am also wondering about driving them 'properly'. So I may be interested in one of the QSCs as well (I have a nuclear power station handy to power it up
). Obviously age and condition come into the decision here as well. They look fairly complex to me with all those output devices. I wouldn't want to be faced with the cost of repairing one too soon.
Ritchie, I guess that you are right because SL uses 3886 chip amps on his! It was that 'sales pitch' in the first post that got me interested!
I've got my 3886 woofer amps (one per driver) 90% built so will start off with those but it would be very interesting to see how much difference more power ('better' amps) would make. TNT reviewer looking for ...........
I though I'd add my bit to this interesting thread. For the record, my brother runs a sound rental company and I provide honorary technical support while holding a full time government job. We have Dynacord S1200, QSC RMX2450, QSC RMX4050HD, a Chinese amp called Tony Lee among others.
All of these amps have a hollow midrange and a not so great top end. The bass performance is pretty good with the Dynacord being the worst and the Chinese amp being the best. Mind you, we use 2 way bass-reflex Yamaha speakers to full active three way running Bill Fitzmaurice's Tubas and DRs.
Any good hi-end amp will have a better mid and high performance. But in the bass, you need to build a very beefy output stage and power supply to excell the pro-amps. If you listen critically on a good pair of speakers that go very low, you will hear that the pro-amps miss out some of the nuances of bass that get covered up by the extra punch.
All of these amps have a hollow midrange and a not so great top end. The bass performance is pretty good with the Dynacord being the worst and the Chinese amp being the best. Mind you, we use 2 way bass-reflex Yamaha speakers to full active three way running Bill Fitzmaurice's Tubas and DRs.
Any good hi-end amp will have a better mid and high performance. But in the bass, you need to build a very beefy output stage and power supply to excell the pro-amps. If you listen critically on a good pair of speakers that go very low, you will hear that the pro-amps miss out some of the nuances of bass that get covered up by the extra punch.
Pro Amps certainly have the advantage of beiing "pro". They are built to be reliable. I wonder, however. There are lots of Pro amps in different price catergories, all with different specs and different sound. In PA-world, Amcron (by Crown) are concidered top of the bill, by some. Amcron amps have an ODEP circuit, that prevents clipping. In essence, it's class F amplification, switching to a more powerful amp, when the need arises (more efficiency, less heat), and cutting down on gain when clipping to save the speakers.
What choices do you make when deciding what pro-amp to buy for a home theater, apart from that it sounds ok? It's unlikely that you run into powerproblems with, say, 300 watts per channel, but clipping IS still possible. Would that be a reason to spend more and get Amcron in stead of QSC?
On a side note; in the link above, the guy used an active digital Behringer EQ for LFE equalisation. That's a money saver... on that amout of money a few 100 dollars more would not have mattered and he could have gotten a better sounding EQ...
What choices do you make when deciding what pro-amp to buy for a home theater, apart from that it sounds ok? It's unlikely that you run into powerproblems with, say, 300 watts per channel, but clipping IS still possible. Would that be a reason to spend more and get Amcron in stead of QSC?
On a side note; in the link above, the guy used an active digital Behringer EQ for LFE equalisation. That's a money saver... on that amout of money a few 100 dollars more would not have mattered and he could have gotten a better sounding EQ...
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.