LC ZAPpulse Amplifier Q & A

Status
Not open for further replies.
Jump to Latest
#141
Hi,

The thing is, they're going through a learning experience just like you are, hence the added robustness against this on their latest version, and I think it's great that it's always getting better with each version. The alternative is they take the microsoft approach. Deny all problems, place blame on users lack of knowledge/experience, and keep remarketing the same old junk without ever improving it, while charging you a big fat service fee for fixing it since any problems are your fault anyway.

There's really nothing forcing them to give you a free replacement, they could easily say buy a new one. That would lead to a bad reputation though, a free replacement is excellent business, especially if you didn't even have to fight for it, and it doesn't sound like you had to. I'd be very pleased with that outcome, there's just nothing more you can ask for.

Sure it would be nice to have it upgraded with the latest greatest version, but things just don't ever work that way.

Now you know what the death hum sounds like anyway, it's a strong indicator of a blown output stage.

Hope you have better luck from now on.

Regards,
Chris
 
#142
classd4sure said:
Hi,

The thing is, they're going through a learning experience just like you are, hence the added robustness against this on their latest version, and I think it's great that it's always getting better with each version. The alternative is they take the microsoft approach. Deny all problems, place blame on users lack of knowledge/experience, and keep remarketing the same old junk without ever improving it, while charging you a big fat service fee for fixing it since any problems are your fault anyway.

There's really nothing forcing them to give you a free replacement, they could easily say buy a new one. That would lead to a bad reputation though, a free replacement is excellent business, especially if you didn't even have to fight for it, and it doesn't sound like you had to. I'd be very pleased with that outcome, there's just nothing more you can ask for.

Sure it would be nice to have it upgraded with the latest greatest version, but things just don't ever work that way.

Now you know what the death hum sounds like anyway, it's a strong indicator of a blown output stage.

Hope you have better luck from now on.

Regards,
Chris
Click to expand...
Well learning experience is one thing making a amplifier working without speakers connected is another.They have been making amplifiers for several years now and the others"analog" they are selling doesn`t suffer from this problem so they should know how it works.I`m not asking to get the latest version only to fix this problem so it won`t happen again.At least there must be someway to fool the amp that a speaker is connected or you should not be able to start it up without ,or something like that.I got a new one of course they come with warranty,if they did`nt nobody would dare buy them.And by the way mine was connected and it also burned my woofer and that i have to buy myself and it was a lot more expensive than the module.The thing i probably did wrong was to change RCA cable to fast there was maybe some power left on the module when i did it,the left module survived so the power on that one had probably time to end.
 
#143
One thing, when your module's output stage burnt, it created a rail to rail short, which would drain the supply pretty quick I'd imagine. Point is I wouldn't try and use the period of time it took you to do the second module as any kind of measure on how long you should wait before changing any connections, it's likely to be longer yet.

Does your supply have bleeder resistors ?
 
#144
I feel for your frustration, but you have to see also that class-d is a totally different and relatively new technology to all previous amps.

I suspect that LC Audio may have implemented a method of preventing the output damage when using without a load by using a voltage dependent resistor across the output. If so, this should be an easy add-on to your existing module. I'm sure if you ask them nicely they will be able to sort you out or at least tell you what to do. But I could be wrong so don't hold them to it that it can be done like this 🙂
 
#145
richie00boy said:
I feel for your frustration, but you have to see also that class-d is a totally different and relatively new technology to all previous amps.

I suspect that LC Audio may have implemented a method of preventing the output damage when using without a load by using a voltage dependent resistor across the output. If so, this should be an easy add-on to your existing module. I'm sure if you ask them nicely they will be able to sort you out or at least tell you what to do. But I could be wrong so don't hold them to it that it can be done like this 🙂
Click to expand...
Yes i noticed that they have implemented such thing,i asked them about it but they said it was a lot more than that.It was a whole new circuit and all print was changed???Probably they se more money in selling me the new 2.3SE instead.Read somwhere that the 2.3SE sounded harsh in the treble and not so good as the 2.2SE maybe the voltage resistor is the problem,in that case i rather keep my 2.2SE now when i know not to start up without all cables connected.I`m not dissapointed in LCAudio in any way i own a lot of the stuff they make and for the money nothing can compare,i even changed my Krell stuff for their products because they sounded better.
 
#148
I think they left the irfb31 from zappulse 2.2. Now they use an even more powerful mosfet. Cant remember the number but i think it was something lik fb38n200 or something like thath. One irf640 is still implemented and are used in the gate drive.
 
#154
Lars Clausen said:
We use IRFB38N20 in ZAPpulse versions 2.2 and 2.3

Working on updates for the .com site.

Brenda has also placed a nice picture of herself Here
She is not only nice looking, but also a very skilled technician. If you have a ZAPpulse 2.2SE or 2.3SE, it is highly probable it was assembled and tested by her.
Click to expand...

My god, Please!, keep her out of sight when you are working with power from the mains...
Now pieces are starting to fall together; it's Her voice making my speakers tremble...
 
#156
Joep Zonnebloem said:


My god, Please!, keep her out of sight when you are working with power from the mains...
Now pieces are starting to fall together; it's Her voice making my speakers tremble...
Click to expand...


But then again, if things fall apart, you can use that as an excuse to call Brenda.

Btw Pic10.jpg, so there is more 🙂

Btw Lars, nice to see you again on the forum. Guess you have been very busy the last few months (with work I mean 😉 )
 
#157
vroum90: It can run 1 MHz, but it does not give any benefits. Better to use the free running mode. Sounds better.

In ZAPpulse we have found that BC sounds warmer and softer than BG. However they are NOT in the LC filter, they would both explode if placed there.

Duck Twacy: Thanks, yes i have been very busy preparing the new Sidewinder 3. A rather advanced product... Takes a lot of resources.

Pic10: Yes but she is not showing ... :bawling:
 
#158
Just finished my 2.3's and they sound great. THey might be a bit harsh in the treble, but I have to listen more before I say that for sure.

Anyway, I need help with the gate power. I have a predator power supply and 2*500VA transformers. I also have a 15V gate transformer connected to the supply but haven'r dared to connect it because of the following:

1. At the input of the predator I get 18VAC, which should be ok (no load). But at the output from the predator's gate supply I get 32.6VDC ???

2. I think I should remove a small solder bubble on the zap to use the external gate, is it just to remove it with a solder pump?

3. I guess the gate wire ould be a thin one, it is quite a tuny hole...

Thanks for any help!!!

Robert
 
#159
robomatique said:
Just finished my 2.3's and they sound great. THey might be a bit harsh in the treble, but I have to listen more before I say that for sure.

Anyway, I need help with the gate power. I have a predator power supply and 2*500VA transformers. I also have a 15V gate transformer connected to the supply but haven'r dared to connect it because of the following:

1. At the input of the predator I get 18VAC, which should be ok (no load). But at the output from the predator's gate supply I get 32.6VDC ???

2. I think I should remove a small solder bubble on the zap to use the external gate, is it just to remove it with a solder pump?

3. I guess the gate wire ould be a thin one, it is quite a tuny hole...

Thanks for any help!!!

Robert
Click to expand...

Hello Robert,
That's what the cookbook says (about the bubble). I always use soldering braid. It's tiny woven copper (like a shielding mantle) and it is easy and works great. But maybe for this delicate work a pump might be better. About the 32V: are you sure its not 2x15V? In that case you should parallel the secundary windings.

Best regards, Joep


PS: As you are going to heat your soldering iron anyway, why don't you try the "compensated mode" (just a little wire)? Maybe the harshness will diminuish. I have not tried that yet but I'm curious whether you can hear the difference.
 
#160
Joep Zonnebloem said:


Hello Robert,
That's what the cookbook says (about the bubble). I always use soldering braid. It's tiny woven copper (like a shielding mantle) and it is easy and works great. But maybe for this delicate work a pump might be better. About the 32V: are you sure its not 2x15V? In that case you should parallel the secundary windings.

Best regards, Joep


PS: As you are going to heat your soldering iron anyway, why don't you try the "compensated mode" (just a little wire)? Maybe the harshness will diminuish. I have not tried that yet but I'm curious whether you can hear the difference.
Click to expand...

THanks!

The treble is not that harsh, I will wait for a while before modding. It would be nice to connect some kind of jumper switch to be able to try it out. Do you know if a wire link or the 100pF capacitor compensated mode is the best way to go?

It is a 2*15V transformer, I have paralleled them by connecting them together at the socket input (primaries and secondaries together into the connector). I will triple check later tonight, but it is strange that I get 18V AC at the connector and 32 DC at the output?

Thanks for your help, Now I have somthing to go on!

Robert
 
Status
Not open for further replies.
Top Bottom