Budget amp lines from QSC, Crown and Thomann??

[J Pearce]

I can recommend the QSC GX5 range - exceptionally light weight and a lot cheaper then their other stuff.

 

Have you had any trouble with crosstalk? I had so much trouble with crosstalk on two of these that I couldn't use them for separate monitor mixes... I beleive it was related to the built in crossover (Sub on Ch1, Top on Ch2).

[Rob_Beech]

The 4 700's are fantastic amps, I've not managed to get one to fail yet under lots and lots of stress. 2 lots of 4ohm bridged and they keep going and going. YMMV of course but I can't find fault with them.

 

Rob

[KevinE]

I've had 2400/1500/400s in a rack, abused and neglected for quite a while - often running into no load

 

Paul: Please dont run the TA series into no load. This is a good way (in the larger versions) of causing the mosfet rail switch RC caps to go short, which then overheats the associated resistors. If you're lucky, the resistors will safely fail open and the amp will continue to work without them until such time as the rail switches punch through if the amps are subsequently driven too hard. But more usually, the resistors (in series with s/c caps) tend to cook slowly and eventually charr the pcb.

[Solstace]

Well, our TSA 4-700 arrived a few weeks ago and has since been doing duty in one of our smaller PA systems.

 

The 4-700 just seems too good to be true. It doesn't thump when turned on or off, it does seem to have the headroom expected (I've not taken measurements), and it seems to run cool as a cucumber for hours on end. It feels well-built for the money - though I've not popped the lid to see what's inside yet. Also bear in mind this is for a fixed install that will run at mouse-whisper level for a couple of hours a week. Either way we're happy so far - let's see how long they all last!

 

For the louder stuff we opted to fit some Crown XLS802's - and so far I'm really very happy with them. Worlds away from the amps they replaced in terms of sound and build quality. Feels like I've got a whole new sound system in that building! As one of our operators recently put it, it's like the faders and desk EQ knobs are now actually connected to the speakers in some fashion! )

[olly DMT]

The QSC amps are great we have 2 1800 and a 4000 powerlight which run 4 res4 speakers the 4000 began giving a little trouble last year but nothing serious, hopfully will have an E100 amp soon to compare them to. Will feel strange just having one amp to run the tops after so long of lugging such a big rack round!

[safetyman]

Well, our TSA 4-700 arrived a few weeks ago and has since been doing duty in one of our smaller PA systems.

 

The 4-700 just seems too good to be true. It doesn't thump when turned on or off, it does seem to have the headroom expected (I've not taken measurements), and it seems to run cool as a cucumber for hours on end. It feels well-built for the money - though I've not popped the lid to see what's inside yet. Also bear in mind this is for a fixed install that will run at mouse-whisper level for a couple of hours a week. Either way we're happy so far - let's see how long they all last!

 

For the louder stuff we opted to fit some Crown XLS802's - and so far I'm really very happy with them. Worlds away from the amps they replaced in terms of sound and build quality. Feels like I've got a whole new sound system in that building! As one of our operators recently put it, it's like the faders and desk EQ knobs are now actually connected to the speakers in some fashion! :( )

Hope you like your new amps and that they do great service.

Personally, I have always found Matrix amps to be very affordable, very conservatively rated and knock the socks off anything else on the market, bar none. They have massive power supplies and, therefore, huge headroom as compared to anything else. Their current lightweight range of UKP 1300 & UKP2100 weigh only 5-7 kg and they are all-British made/hand-built in Wales. Contact amps-4u.co.uk on ebay or go to Speakerplans.com , have a look at the amp forum and contact( PM ) andyamp who is the guy that makes Matrix amps.

[jamesperrett]

Personally, I have always found Matrix amps to be very affordable, very conservatively rated and knock the socks off anything else on the market, bar none.

 

We had a couple of their UK Power amps a few years ago. They went badly wrong and we couldn't find anyone who knew anything about them to help with repairs. None of their old suppliers could tell us how to contact the company and it looked like they had gone bust. We ended up replacing them with QSC RMX amps which have worked fine ever since.

 

Cheers

 

James.

[bruce]

My Thomann D4-500 arrived today, but it is not yet screwed into a rack.

One day it will be, I'll plug it up, and report back :(

 

Please do - I've got a very similar celestion rig, and my back would appreciate any lightening of the amp rack ;)

[Rob_Beech]

James.

 

Get in touch with Andy he'll be more than happy to help.

[jamesperrett]

Get in touch with Andy he'll be more than happy to help.

 

Too late I'm afraid Rob. We had no option but to throw them in the skip when we couldn't find anyone who knew anything about them. The guy who was fixing them wasn't too keen on delving too deeply into them without a circuit diagram but I know he removed a number of blown output transistors.

 

Maybe Andy should make contact with the people that used to sell Matrix amps (in our case either Studiospares or CPC) and let them know that he still supports these amps.

 

Cheers

 

James.

[safetyman]

Yes,

 

Andy is always willing to help, and he can fix any of his amps, even those going back 15 or more years. Some of these old amps are still in use today, and most, have never needed a service, let alone gone wrong.

[dbuckley]

Please do - I've got a very similar celestion rig, and my back would appreciate any lightening of the amp rack ;)

Well, the amp rack is much lighter, its 4u plastic rack rather than a 10u proper job on wheels, so its a one hand lift rather than two person.

 

On the other hand, the amp seems way underpowered. The SRC-1 controller's -2dB (*) light has yet to illuminate, even with the amp channels at clip. It also seem a little brash, and seems to lose power on transients well before the clip light comes on. The MTRs could get the -4dB light on with little provocation and without hitting clip.

 

So I have very mixed feelings. For most of what I do, I dont need to run at high SPL, so its probably just fine. However, with the pair of heavy metal MTR amps, the celestions used to sing, and sing loudly (upper 90s in village hall type venues) and now (based on making a racket in the garage) they don't, so I'm "apprehensive" about tackling a musical with this setup.

 

So I guess I'm disappointed.

 

I'm also annoyed I've managed to wire the sub channels out of phase with each other, which is unusual of me, I'm quite fastidious about stuff like that :) Some wiring tracing to do tomorrow.

 

Whats really bugging me is that I ripped out my wiring from the big rack and trimmed it to fit into the little 'un, so theres no going back without a shedload of work :(

 

* - Footnote - for interested readers not familiar with the Celection SR setup, the controller measures the power delivered to the speaker and uses that as the input to a model (done in analoge electronics!), so the controller knows how hot the voice coil is, and if it is getting too hot then the controller reduces the signal to the amp, by -2dB, -4dB, or -20dB to allow the coil to cool. Theres a LED on the front panel for each step of reduction so you can see when you're attempting to overcook the speaker. A few other manufacturers do the modelling trick these days, using "sense" connections, but Celestion were there many years ago, and did it better, as the SR controller measures both volts and amps across and through the speaker, and hence can calculate the actual wattage being dissapated by the voice coil; most modern controllers just measure voltage and make assumptions about current flow to guess the wattage.

[Hypersound]

Probably a bit of a stupid question but is it by any chance a problem with the input sensitivity? I was looking at one of these and couldn't find specs or manual on the Thomann site. If I was to buy one I would be using it for foldback and without a LMS in the chain, there would be no way to match to an unusual input sensitivity. I am don't think your controller would do that either.

 

Just a thought.

 

Andy

[Malcolm Gordon]

I have recently acquired a TSA 4-700 to run PA and foldback in small venues and alternatively up to 4 channels of effects for plays.

There may be occasions when I just need two channels but, bearing in mind

Paul: Please dont run the TA series into no load....

would the same apply to the TSA ? Should I

a) use channels A and C in bridge mode, even if I don't need the extra power ?

or

b) use channels A and B and connect dummy loads to channels C and D, with no inputs and the attenuation turned right down ?

 

If the latter, what should I use for a dummy load ?

 

Thanks for any guidance anyone can offer.

 

Malcolm

[KevinE]

It's just the TA series and clones that can do this. Of course if you keep the pot down on the channel that's unloaded, it'll be fine either way. I have no experience of the TSA range at all so cant comment!