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Non ADA Gear => Amps => Topic started by: rabidgerry on April 28, 2018, 07:20:42 AM

Title: Koch ATR-4502 Power Amp
Post by: rabidgerry on April 28, 2018, 07:20:42 AM
Hi guy's, has anyone any experience with this brand of amp?

I am very interested in this model

http://www.koch-amps.com/guitar-poweramp-atr-4502.html (http://www.koch-amps.com/guitar-poweramp-atr-4502.html)

Given that it is only 90watts though I worry it will not be loud enough since I currently use a 300watt rocktron velocity amp.

Anyways, Koch are interested in endorsing me and if I had to use some of their product this would be the first thing I would want to try.  At 5.5kg it would be perfect for taking on the plane like the one I shall board this Tuesday on my way to play in Malta  :headbanger:

Be interested to hear any opinion on this brand and also this amp if any of you have tried it.
Title: Re: Koch ATR-4502 Power Amp
Post by: Systematic Chaos on April 28, 2018, 04:48:22 PM
Wow, Koch amps are some serious "almost Boutique" stuff, Dutch amp manufacturer with a really high renommee.
Don't be intrigued by the wattage. e.g. a Boogie, Marshall or Engl 2x20w tube poweramp blows the 300w Rocktron straight outta the water volume wise.
Although the ATR-4502 is a hybrid, it gives you more of that tube warmth, depth and punch than the Rocktron or Thomann.
It´s the same power sections as in their Jupiter Amps, basically 2 Jupiter 45 poweramp stages.
Check that amp for some sound bits.
...and don't judge the book by its cover (watts wise).
If you can secure a good deal with them go for it  :thumb-up:
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on April 29, 2018, 04:37:31 AM
Wow, Koch amps are some serious "almost Boutique" stuff, Dutch amp manufacturer with a really high renommee.
Don't be intrigued by the wattage. e.g. a Boogie, Marshall or Engl 2x20w tube poweramp blows the 300w Rocktron straight outta the water volume wise.
Although the ATR-4502 is a hybrid, it gives you more of that tube warmth, depth and punch than the Rocktron or Thomann.
It´s the same power sections as in their Jupiter Amps, basically 2 Jupiter 45 poweramp stages.
Check that amp for some sound bits.
...and don't judge the book by its cover (watts wise).
If you can secure a good deal with them go for it  :thumb-up:

Wattage arguments..................here we go again.  Man 300watt Roctron is pretty loud.  I've never had past 2/3rds of the way, and the only reason I was up that high was I was using 16ohm cabs.

The only reason I mention the wattage thing is because it's not a full tube amp.  So you've just compared a Boogie, Marshall or Engl 2x20w tube poweramp with a 90watt hybrid amp which only has two 12ax7 tubes in it either side.  I think my being dubious isn't so silly.

Sure we all know 50watt tube amp is as loud as an SS amp 300watt or more but this is some kind of weird class D thing with two tubes inside it.  If someone tells me that I treat the hybrid as though it were tube then hell yeah 90watts (nearly 100watts) is fine.

This amp is 5 kilo lighter than a velocity and about the same weight as my Thomann Harley Benton class D SS amp so if I score an amp with something similar to the Velocity "tubey" feel but a lot lighter then I am on to a winner.  I cannot take my rocktron on the plane with me as it's to heavy as hand luggage when coupled with a preamp (I've stripped my rack back at the minute down to preamp and power amp purely for traveling abroad normally I have a power conditioner and noise gate included)  so it looks like I'm taking the lighter Harley Benton (good but not the velocity) instead and a little noise gate pedal to fill in for the ns-50.

Title: Re: Koch ATR-4502 Power Amp
Post by: Systematic Chaos on April 29, 2018, 06:12:53 AM
Gerry, I merely said/meant hear them out what they wanna offer and if its good go for it. Who knows, maybe you'll end up with a Pedaltone II and an ATR-4502 (I sure as hell wouldn´t mind that combo).
Peace bro!!
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on April 29, 2018, 06:38:50 AM
Oh I know, I'm just curious to see if this 90watt hybrid is as loud as a SS 300watt amp.  That's my bench mark currently so I need the same or me for me to make it work with my rack gear.

I looked at the pedal tone, not sure I would use half of that, who needs clean channels  :lol: :lol: :lol:, however as a portable preamp for plane journeys the superlead preamp pedal seems more of a solution to me.

They've initially asked me what I'm interested in so I've put forward the ATR-4502.  This surely has to be loud enough to compete with other guitar power amps.  Fingers crossed it is, the concept is unique to poweramps I believe and interesting.
Title: Re: Koch ATR-4502 Power Amp
Post by: Kim on April 29, 2018, 01:39:28 PM
Oh I know, I'm just curious to see if this 90watt hybrid is as loud as a SS 300watt amp.  That's my bench mark currently so I need the same or me for me to make it work with my rack gear.

There's two things to also consider here. 

The perceived volume is not linear with wattage ratings. 
If you compare the maximum volume of say a 50 watt amp with a 100 watt amp, the difference is only going to be 3 dB....not much of a difference.  It would take an amplifier with 10 times more power  to be perceived as being twice as loud; a 10 dB increase.  It'll take 500 watts to sound twice as loud as 50 watts.   :o

A "hybrid" amp is...... still a Solid State amp. 
There's a tube or two attempting to add some "warmth" of the soft-clipping even-order harmonic distortion, but the final link to the speakers is still within the S.S. realm with transistors, Mosfets, etc.  Comparing the 90 watt hybrid to the 300 watt SS amp is comparing two Solid State poweramps.  Apples = apples.

Having put that out there now, if the 90 watt amp fits your travel weight requirements, then IMO it should do the job.  3-4 dB difference shouldn't be the deciding factor here.  And since the price might be perfect (free endorsement?) if the deal is made....well if I were in your shoes I'd just say "Yes please".  :)
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on April 29, 2018, 03:01:18 PM
Hmm I'm not convinced now a 90watt hybrid amp could provide the right amount of volume. 

I had a crate power block before which was 150watts SS and it wasn't loud enough.  I needed two of them to compete with our drummer.  Then I had enough and little more in the tank should I need it.  I have a 400watt SS amp, does the job and with some to spare and then also the Roctron 300watt amps and they roughly work out similar performance to the 400watt amp, so I'm not convinced 90 can cut it.

It wont be free either, but some kind of discount deal as they're too small a company (their words not mine).

I'll have to ask them how does their amp stack up to tube amp volume then and see what they say.

No point in buying something that will not be of use to me.  What I was hoping for was a lighter and potentially even better sounding amp than the Velocity.  I love the Velocity, it's great.
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on April 30, 2018, 04:18:18 AM
Hey RG, seems it's much like the ADA MT100 but modern  :dunno: .  I had a MT100 briefly, I found it under powered and wasn't keen on the tone, to be fair it didn't last long before I swapped it..
I've been using a Carvin DCM200L in my rack for a while now, plenty to get over the drummer and sounds quite good.  It's not class D (many Carvin amps are) which I prefer.  Class D adds yet another transduction layer (similar in concept (albeit works quite differently (pulse trains)) to sampling analogue signals into digital and back again, hence transduction (is that a word ?).

Can you try it and send it back if it isn't right for you ? Basically I recon you have to hear it.

From Wikipedia
A class-D amplifier or switching amplifier is an electronic amplifier in which the amplifying devices (transistors, usually MOSFETs) operate as electronic switches, and not as linear gain devices as in other amplifiers. They are rapidly switching back and forth between the supply rails, being fed by a modulator using pulse width, pulse density, or related techniques to encode the audio input into a pulse train. The audio escapes through a simple low-pass filter into the loudspeaker. The high-frequency pulses, which can be as high as 6 MHz, are blocked. Since the pairs of output transistors are never conducting at the same time, there is no other path for current flow apart from the low-pass filter/loudspeaker. For this reason, efficiency can exceed 90%.
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on April 30, 2018, 05:20:19 AM
Interesting, didn't realise ADA MT100  was a hybrid, I thought it was all tube.  What didn't you like about the influence of that amp on your tone?  Just curious.

Doubt it's like this Koch amp.  But the under powered is the big issue here (providing it sounds good).  I doubt will be able to try before I buy to be honest.

I think my Harley Benton 400watt power amp is class D.  Light and Loud and Cheap.
Title: Re: Koch ATR-4502 Power Amp
Post by: MarshallJMP on April 30, 2018, 05:39:29 AM
ADA does have a 2 x 50W full tube rack amp called the T100S and it weights about 12kg in a 2U rack housing. Mine puts out around 75W per side.
But I can agree that an MT100 is not loud at all, especially compared to a tube amp. Sound wise they are not so bad at all IMO.

I do agree with Gerry that maybe that Koch amp won't be loud enough.

@R, a class D amp is NOT digital actually. There is no AD or DA converter in it. PWM is made when you compare the original signal with a triangle wave, this will output PWM signals which are then amplified by MosFet's (due to their low Rds on resistance) and at the output they just filter out the high frequency's with a low pass filter restoring the original signal. And due to the fact they can get an efficiency  of 90%+ they can use smaller (switching) power supplies and less cooling, so they are lighter then other power amps.
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on May 01, 2018, 03:55:55 AM
Hey MJMP, I know, we've had this discussion before  :thumb-up: , that's why I say it's similar "conceptually" as in, it takes the analogue signal, turns it into something else (in this case pulse trails (by comparing the signal with a triangle wave (so a form of sampling, but not digital sampling)) and then converts it back in to analogue audio, and as you say filters out the objectionable artifacts created in the process. And yes they are very efficient and light etc.  Amazing idea (how do they come up with this stuff).  I have a 4 x 500w Carvin DCM2004L class D amp for PA stuff (10lbs <> 4.53 kgs) pretty light for 2000w.
Can't see RG carting around a 2 RU TS100 LoL but I'm sure he'd love one (as would I  >:D ).

Hey RG, to be fair I didn't give the MT100 much of a chance, it had an annoying hum (which pissed me off), I had to run it off a step down trany as it was a US model. Apart from being under powered (for my needs) it didn't grab me tone wise so MJMPs opinion is probably more relevant than mine in that regard.
I swapped it with Dante for a US B200s which we installed a toroidal 240v trany (I think he got a good run from the MT100  :dunno: and the B200s went to a good home).  The MT100 needed 2 new 240v tranys, one for power and one for the tubes (IIRC) to use here in Oz, it has 1 toroidal and one normal trany in it.  They also made the MT200, same idea, hybrid but double the power and still 1 RU (these are the amps some members have been having neon cut out issues with). From all reports here the MT200 is a good amp.  But needing/having 2 tranys ups the weight (8 lbs <> 3.6 kgs) (http://web.archive.org/web/20040216185247/http://www.adadepot.com:80/adagear/subgear/poweramps.htm).  The Carvin DCM200L is 4lbs <> 1.8 kgs, 1RU and all analogue (and sounds nice on guitar).
Title: Re: Koch ATR-4502 Power Amp
Post by: MarshallJMP on May 01, 2018, 11:14:51 AM
The MT200 has a different power supply (switching) and doesn't come in a 240V version (at least I never saw one).
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on May 03, 2018, 08:43:10 AM
Ok Koch had this to say:

Quote
Because of the ATR technology you don’t need to have the same amount of watts like a class D amp. But they ATR also gives you the same (Full tube amp power sound)on any level. It sound and reacts like a full tube power amp with attenuator build in. But also the high voltage fets gives you a lot of tight bottom end!


He also went onto say Gary Holt of Slayer and Dave Linsk of Overkill swapped 1000watt Matrix amps out fr the Koch Atr.  So if loud enough for them then loud enough for me.
Title: Re: Koch ATR-4502 Power Amp
Post by: MarshallJMP on May 03, 2018, 02:10:03 PM
Well Gerry, heard this all before, the only amp that sounds like a tube amp is... a tube amp. The rest is marketing talk. I'm not saying that these are bad amps but a SS amp will never, ever react like a tube amp even with some preamp tubes in it.
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on May 04, 2018, 02:10:45 AM
Well Gerry, heard this all before, the only amp that sounds like a tube amp is... a tube amp. The rest is marketing talk. I'm not saying that these are bad amps but a SS amp will never, ever react like a tube amp even with some preamp tubes in it.
+1  :thumb-up:
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on May 04, 2018, 03:10:48 AM
I think you guys have missed the point of my post and forgotten what my concern was.  Volume!

As for tube  sound, perhaps its better to look at this like not so much sounding like a tube amp, but sounding better or closer to a tube amp than ordinary solid state.  I don't care about getting authentic exact tube replication but I do want to enjoy an amp that might sound better than other s.s choices at 5kg.

I don't have this Koch amp to compare yet, but the difference between an ordinary S.S amp and Roctron Velocity is night and day. There is a more dynamic feel and that's great.  A glassy element to the sound.

As for those name guitarists I mentioned, they were referenced on the basis that they have switched from 1000watts Matrix s.s amp to this Koch 90watt amp.  So those guys would not have done so if there was not enough power.  Therefore the Koch must do something better or more efficiently to not need the same amount of watts like the guy said.  And, those guys are on a higher level than me, they'd not use the amp if they didn't like the sound over the other either.

Title: Re: Koch ATR-4502 Power Amp
Post by: MarshallJMP on May 04, 2018, 03:26:58 AM
Well and I speak from personal experience, a 90W SS amp isn't loud and you may disappointed with it when it comes to volume. Now on the other hand for live use you don't need a lot of watts when you're mic'd up.
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on May 04, 2018, 03:43:40 AM
Hey RG, I know where you are coming from, The Carvin DCM200L is much lighter at 1.8 kgs (which fits your main requirement ie less weight), 100 w per side (4 ohm) and sounds great with a tube preamp, I've been using it for quite a while now (with both MB1 and MP2) and am very happy with it (and that's compared to my B200s and my Carvin (all tube) TS100).  It's plenty loud even into a 16 ohm load (so less watts, albeit more sensitive speakers as 16 ohm speakers always are), I've never needed to run it full chat even with a real (loud) drum kit to get over.  I'm not saying the Koch (unfortunate name LoL) isn't good, I haven't tried one, try it and then you can tell me.

I do however agree with MJMPs remarks re tube amps, but this is not helpful for you as you need to save weight (didn't mean to get up your nose  :wave: ).  The Carvin TS100 is heaps lighter than the ADA T100s (about half IIRC) but it's still a 2 RU brick (it has 3 transformers (1 power, and 2 output).
Title: Re: Koch ATR-4502 Power Amp
Post by: MarshallJMP on May 04, 2018, 08:17:42 AM
I know that it's not easy to find a light, loud and good sounding amp. At some point you always have to sacrifice something.
Title: Re: Koch ATR-4502 Power Amp
Post by: Kim on May 04, 2018, 10:22:23 AM
I know that it's not easy to find a light, loud and good sounding amp. At some point you always have to sacrifice something.

There's a saying I know of:

The 3 important things about building a race car are Fast, Reliable, and Cheap.  You can only have TWO of those things.

So applying that logic to amplifiers:
Loud, Light, Cheap.  You only get two.  Lol
Title: Re: Koch ATR-4502 Power Amp
Post by: Systematic Chaos on May 04, 2018, 04:21:00 PM
I think you guys have missed the point of my post and forgotten what my concern was.  Volume!

As for tube  sound, perhaps its better to look at this like not so much sounding like a tube amp, but sounding better or closer to a tube amp than ordinary solid state.  I don't care about getting authentic exact tube replication but I do want to enjoy an amp that might sound better than other s.s choices at 5kg.

I don't have this Koch amp to compare yet, but the difference between an ordinary S.S amp and Roctron Velocity is night and day. There is a more dynamic feel and that's great.  A glassy element to the sound.

As for those name guitarists I mentioned, they were referenced on the basis that they have switched from 1000watts Matrix s.s amp to this Koch 90watt amp.  So those guys would not have done so if there was not enough power.  Therefore the Koch must do something better or more efficiently to not need the same amount of watts like the guy said.  And, those guys are on a higher level than me, they'd not use the amp if they didn't like the sound over the other either.

Hey Gerry, I guess you answered some of your questions with this. I read up some on the Koch and there´s pretty good reviews on Rig-Talk, Sevenstring.org, FAS-Forum etc, also with regard to volume, sound and feel.
Everything now is purely hypothetical until you check one out for yourself.
I don't know (and I don't wanna know  8) ) how much of a discount they're offering. Wok something out with a money back option in case it doesn't float your boat and have them send you one. Or take your GF on a nice weekend trip to the Netherlands and check the amp out at Koch directly.

...and since I always have a pocket full of them, some more of my 2cents:
I presently run (main rig) an AxeFX II with an old Rocktron Velocity 150 through an early 90s Boogie 2x12 Vertical Halfback and I have zero volume issues with loud drummer or tube stacks (and I don't get past 2 o'clock on the 150s Vol knobs)

Also, one of the best comments in this thread:
[...] Now on the other hand for live use you don't need a lot of watts when you're mic'd up.
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on May 05, 2018, 03:29:30 AM
Well as I said before, I had 150watt Crate Powerblock and it wasn't loud enough to rehearse so I used to use two of them.

For me and 9/10 live situations I still need an amp that is loud, so the notion of using a low volume amp because I will have monitors is not realistic.  I still rely heavily on what is behind me because I am not surrounded by monitors like how I was the other night playing Sinn fest in Malta.

I need a loud amp and one with excess just in case.

@SC yeah I will have to ask the guy can I send back if the amp is not powerful enough for me.  Those guy's in Overkill and Slayer surely wouldn't use an amp that was not capable of suitable volume.  We shall have to see.
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on May 09, 2018, 04:26:58 AM
Excellent, Koch are arranging a testing for the amp.  Apparently a number of Matrix amp users (1000watt class D) have switched to the ATR-4502 so I have faith on this claim.

Really looking forward to trying the amp out.

The gig last week I played using my little Harley Benton Class D 400watt, sounded quite good.  Perhaps a little Bright but that can be sorted out.  The Velocity is still better, but I wasn't let down by the HB Amp at all.  Very tight.

Lets see what this Koch can do!!
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on May 09, 2018, 06:42:27 AM
 :whoohoo!: , looking forward to your take on it !!  After watching your Malta thing, you definitely need decent volume on stage (but I already knew that  :facepalm: ).  How much are these Koch do das ?
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on May 09, 2018, 07:56:09 AM
I can't wait either.

The price is 649 euro  (before VAT).  Koch stuff is pretty high end as SC has already mentioned.  Their stuff is very, very expensive.

I'm able to get the amp cheaper obviously under the endorsement deal.  If it all works out it will actually be the most expensive piece of equipment I will own.
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on May 10, 2018, 06:52:27 AM
Well hopefully the amp is killer and you are a good ambassador for them :headbanger: .  I'm sure I'm not the only one watching this post with baited breath.. your opinion I'm very interested in  :thumb-up:   Ok so that's a bit over $1k AUD, not a cheap amp, tell them if they keep it under $1k AUD Australians can buy it without GST (VAT, tax whatever) if they care  :dunno: .
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on May 10, 2018, 07:08:56 AM
Fingers crossed man!

I may also have a solution to the VAT, but once step at a time  :thumb-up:

They VAT drives up the price to a point where I am not willing to pay so more fingers crossed there.

I 'm encouraged that other amp users have switched the Koch amp, but we shall have to see eh!  I'd love to be an ambassador for them.  They've certainly been very helpful and they have a long list of higher profile names on their artist page already so it's good of them to have given me the time of day.
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on May 10, 2018, 07:40:16 AM
Hey RG, your influence may be wider than you think  :thumb-up: , we are all looking for the best power amp to go with our MPx etc and, well apart from MJMP (he's got roadies LoL), shrinking our rigs.  I would say though, if you can, try a Carvin DCM200L, less than half the weight, and I can attest to their performance.
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on May 10, 2018, 08:41:50 AM
I already have an light powerful clean amp man.  And I'm happy with that amp (Harley Benton GPA400), It has useful bass and treble controls and the Rocktron Velocity (awesome amp btw) which has something similar only a reactance circuit which behaves in a very dynamic "tube" like way (Kim can attest to the Velocity's performance).  However the HB is very light (class D 5kg) and the Velocity is very heavy (9.9kg).  And sure I have best of both worlds but perhaps I can get something with a more "tubey" sound and feel but at the same kind of weight as the Harley Benton.

The Harley Benton is what I took to Malta with me as the Velocity is too heavy.
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on May 11, 2018, 04:18:47 AM
Hey RG, I hope you can get a good deal worked out and the Koch does exactly what you want  :thumb-up: , seems from all reports it should be on the money sound and power wise.
Mike has repaired his B200s so I get my TS100 back  :whoohoo!: , the 2RU brick LoL.  Next rehearsal I'll give it a go (again) which will be a good comparison to the DCM200L while it's fresh in my mind as it's in my live rack (also great on bass with MB1 BTW).
Title: Re: Koch ATR-4502 Power Amp
Post by: Systematic Chaos on May 11, 2018, 03:37:45 PM
Hey Gerry,

I'm looking forward to hearing your impressions once you get the amp.
Not to hi-jack your thread though....I been also eying the Palmer Macht 402 (http://www.palmer-germany.com/mi/en/MACHT-402-19_quot-Stereo-Power-Amp-for-Guitar-PMACHT402.htm). At 3.8kg and 2x100w @8ohms it also looks promising (especially at the price point of 288€ (Thomann)/245GBP (Andertons))
Review: http://blog.adamhall.com/en/2016/04/25/palmer-macht-402-powerhouse-test-report-by-gitarre-bass/ (http://blog.adamhall.com/en/2016/04/25/palmer-macht-402-powerhouse-test-report-by-gitarre-bass/)
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on May 11, 2018, 10:07:20 PM
Very cool SC  :thumb-up:
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on May 12, 2018, 02:23:18 AM
Hey Gerry,

I'm looking forward to hearing your impressions once you get the amp.
Not to hi-jack your thread though....I been also eying the Palmer Macht 402 (http://www.palmer-germany.com/mi/en/MACHT-402-19_quot-Stereo-Power-Amp-for-Guitar-PMACHT402.htm). At 3.8kg and 2x100w @8ohms it also looks promising (especially at the price point of 288€ (Thomann)/245GBP (Andertons))
Review: http://blog.adamhall.com/en/2016/04/25/palmer-macht-402-powerhouse-test-report-by-gitarre-bass/ (http://blog.adamhall.com/en/2016/04/25/palmer-macht-402-powerhouse-test-report-by-gitarre-bass/)

I have also saw this amp and thought it would be a good buy.  I saw one second hand going for a very good price a few weeks ago, but I kinda had my heart set on the Koch.

I like the options that the Palmer has and would consider it had I not got two Velocity's, however, the Velocity Reactance vibe is a lot more appealing.  I dunno what that amp has inside it but it's very dynamic  It's not like a normal SS amp at all.  I heard the 150 isn't as good as the 300 also bare that in mind if you're making a comparison with the Palmer.  I'd love to try the Rocktron Mainline as well  :thumb-up:  But since we are talking weight here, Rockron amp get's ruled out.

The Palmer is very, very light!
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on June 06, 2018, 07:40:56 AM
Ok so the deal fell through, or rather I could not accept it as I was unable to avoid the VAT which drove the price up too much for me.  Shame.
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on July 22, 2018, 01:30:41 PM
The deal is a back on, the dude is gonna try help me out further on the price by seeing if he can get one with some cosmetic flaws that he can sell me with yet a further reduction.

Lets hope this amp at 90watts total is worth it.  I ain't spending £400 + on something that isn't going to destroy small buildings!
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on July 23, 2018, 06:05:13 AM
Hey RG, cool, I hope it works out  :metal: . And interested to get your opinion on it  :thumb-up: .
Ahhh  >:D destroy small buildings, my 72 Marshall 50 is good at that LoL, my record with that amp is you could here it clearly 13km away, through the bush/forest  :whoohoo!:
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on July 23, 2018, 11:34:13 AM
Fire Power!  That's loud Richard.

I really hope this amp is up to the job.  I can't fathom these guy's making an amp that will not be loud enough to play in a live band setup.  I go to 4.5-5 on the volumes of my Rocktron Velocity, at gigs with only two cabs may be about 5-6.  Come on Koch don't fail me  :facepalm:  I have the money, I just need to wait until the factory opens back up again after holidays.
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on August 23, 2018, 04:50:31 AM
Well the deal is back on the table.  Should hopefully have the amp by next week!

Fingers crossed the amp is worth it.
Title: Re: Koch ATR-4502 Power Amp
Post by: Dante on August 23, 2018, 06:34:26 AM
Good luck man, and let us know how it shakes out  :thumb-up:
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on September 03, 2018, 08:12:56 AM
We'll it's here
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on September 04, 2018, 05:09:13 AM
Cool  :whoohoo!: , looks a bit boxy though LoL.
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on September 04, 2018, 09:02:53 AM
 :lol:  It does!

I wont get testing until Saturday.
Title: Re: Koch ATR-4502 Power Amp
Post by: MikeB on September 04, 2018, 01:49:42 PM
Ooh,  Gerry.  You are such a tease!  :nono:
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on September 04, 2018, 03:23:20 PM
haha not on purpose!  If I could test it right away I would!

Keen to see if what I have been told.  So it's 90 watts, but apparently delivers the same amount of DB as a class D 600-700watt amp.  I have a 400watt class D amp and that's loud as hell!  So looking forward to seeing if this claim is true.
Title: Re: Koch ATR-4502 Power Amp
Post by: bunkyloo on September 04, 2018, 05:15:33 PM
Yeah I can't wait for the feedback on .t.
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on September 08, 2018, 02:18:38 AM
Ok tried it last night for a few hours.

It seems loud enough running at 8ohms each side (L-R).  I have yet to test it with our drummer.  My ears where ringing badly when it was up about half way (I didn't use ear plus as I wanted to hear as true as possible).  I'm hoping it does have the volume I need.  Early signs are good.

I found I needed both voicing switches engaged, deep and presence.  One thing I would say is that the should have given the amp pot controls for these functions without having preset switches.  It's much more useful to be able to tailor these regions like on my Velocity power amp.  At gigs I am usually supplied with 4x12" cabs one for each side so I get lots of bottom end, however I don't have 4x12" in my rehearsal room, I have 4 2x12" cabs so I usually need a low end bump somewhere and with the Rocktron I can dial in low end using it's reactance controls.  Not a deal breaker by any means, but I like a controls better than setting switches.

Feel wise, it felt very elastic, spongey, that tubey feel I was told I would get is definitely there.  Harmonics seem a little more alive.  That being said, I think the Roctron Velocity feels very similar.  I need more time with it but I think it is a winner.  It's solidly built, that's for sure.  Clean and simple design.  Lets see what it can do in the band context............................
Title: Re: Koch ATR-4502 Power Amp
Post by: rabidgerry on September 14, 2018, 11:23:50 AM
seems I have a very good amp for FREE!!!  The dude has not responded to my emails trying to pay for the amp and he has sent me one with a blemish or two, most notably the l.e.ds for one of the heat protection circuits is missing or broken.  I wonder can I replace it?

Well the amp appears to be loud as hell!  Very responsive and very dynamic.  Not sure what way the fans work, I thought they would be on all the time but it seems only when the unit gets hotter may be?  I dunno.
Title: Re: Koch ATR-4502 Power Amp
Post by: rnolan on September 14, 2018, 09:02:45 PM
Hey RG, it's good it's loud enough  :thumb-up: