The short version is no, you probably don't need buffering.
The longer version is that you might like how it sounds anyway. If you have a balanced source you either need two SE-buffers (mine would work, but plenty of other options 🙂 ) or you need something that is designed to be balanced. I've done one example with the OPA1632 opamp (here), but again there are several designs out there.
The longer version is that you might like how it sounds anyway. If you have a balanced source you either need two SE-buffers (mine would work, but plenty of other options 🙂 ) or you need something that is designed to be balanced. I've done one example with the OPA1632 opamp (here), but again there are several designs out there.
The jumper on 125 ASX2 put the amp in BTL mode so you can feed it with balanced source IMHO but only one channel available
Interresting informations in this thread and links included concerning input buffer :
What do I need to make the ICEpower amps work?
Interresting informations in this thread and links included concerning input buffer :
What do I need to make the ICEpower amps work?
Haha, I can decode message #47.
"I used modules SE BTL mode. Need ustonovit moschny jumper between two negative outputs of the module.
In its implementation of the buffer I applied on the lamp fahoinvertor Lundahl transformer.
Impressions are the best."
Means
"I used modules SE BTL mode. Need install massive jumper between two negative outputs of the module.
I made tube input buffer with transformer (sounds like tube input stage and transformer acting as phase inventor)
Impressions are the best."
"I used modules SE BTL mode. Need ustonovit moschny jumper between two negative outputs of the module.
In its implementation of the buffer I applied on the lamp fahoinvertor Lundahl transformer.
Impressions are the best."
Means
"I used modules SE BTL mode. Need install massive jumper between two negative outputs of the module.
I made tube input buffer with transformer (sounds like tube input stage and transformer acting as phase inventor)
Impressions are the best."
Hi,
I have 2 50ASX2SE modules lying around and I would like to know what's the definitive opinion regarding the SE to BTL mod.
I've read Nisbeth blog and it seems the it is very easy to do it. Of course you would need a balanced input, but it only requires to desolder one jumper!
On the other hand, post #108 post an official ICEpower reply saying that the mod would not work properly.
So... is it worth it or not?
Also, is there any "already assembled" input buffer board I could buy that works properly with the 50ASX2SE (if I decide to run single ended input, as I asume i don't need buffer when running balanced input)??
I have 2 50ASX2SE modules lying around and I would like to know what's the definitive opinion regarding the SE to BTL mod.
I've read Nisbeth blog and it seems the it is very easy to do it. Of course you would need a balanced input, but it only requires to desolder one jumper!
On the other hand, post #108 post an official ICEpower reply saying that the mod would not work properly.
So... is it worth it or not?
Also, is there any "already assembled" input buffer board I could buy that works properly with the 50ASX2SE (if I decide to run single ended input, as I asume i don't need buffer when running balanced input)??
Hi
About wiring this module. Do I have to connect W100 and W101 to the case and to the AC ground?
Thank you!
About wiring this module. Do I have to connect W100 and W101 to the case and to the AC ground?
Thank you!
The slowdiyer has tried this check here ICEpower 50ASX – SE to BTL conversion | theslowdiyer
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I think Nisbeth is the "slowdiyer", and he says the BTL mod might work, but there is an official response from ICEpower that says it won't.
Regarding the buffer, I already bought a PCB, but if the BTL works I would ditch it and go balanced.
The slowdiyer has tried this and says it works fine. ICEpower 50ASX – SE to BTL conversion | theslowdiyer
He said: "I haven’t actually measured anything (not sure what to measure to be honest) but I get clean audio out on the BTL speaker connector (P104) and a very loud buzzing noise on the other output, so at least it isn’t running stereo anymore. No guarantees on anything yet though, but it’s definitely promising."
Icepower said: "Using the SE module in BTL mode will cause Bad audio performance in BTL mode with high distortion (since the two channels are not switching in sync as they should when running in BTL, because they are designed for SE mode – Also the two common mode chokes will not work (bad EMC performance)."
I think one thing is to get sound in one end, and the other is to get proper performance.
This is the reason ICEPower take out the speaker unused speaker connector on the BTL model. You will notice that ICEPower do not quantify the extra distortion. However I do take your point about measurement.
As mentioned several times you're right that I haven't measured anything so I can't prove my theory, however I am not the only one who has done this mod and claimed it a success.
Also, I am 99.x% sure that the ICEpower reply refers to bridging without moving the BTL-jumper, because I believe the BTL jumper is what syncs the channels (like the BTL-sync pin on the 125ASX). If you can verify poorer EMC-performance on a converted module you can always remove the choke, but I don't have a way to test for EMC so I did not bother doing that.
Last but not least: As I've written somewhere else that I know for a fact that the reason that there are two versions of the 50ASX was that omitting parts on the BTL version made it a bit cheaper and thus a candidate for going into small subwoofers etc. However, I don't know whether that translates to any other (minor) design changes other than omitting the superfluous components. The first (non-production) modules were convertable like the 125ASX and in exactly the same form factor as the ones sold now.
Also, I am 99.x% sure that the ICEpower reply refers to bridging without moving the BTL-jumper, because I believe the BTL jumper is what syncs the channels (like the BTL-sync pin on the 125ASX). If you can verify poorer EMC-performance on a converted module you can always remove the choke, but I don't have a way to test for EMC so I did not bother doing that.
Last but not least: As I've written somewhere else that I know for a fact that the reason that there are two versions of the 50ASX was that omitting parts on the BTL version made it a bit cheaper and thus a candidate for going into small subwoofers etc. However, I don't know whether that translates to any other (minor) design changes other than omitting the superfluous components. The first (non-production) modules were convertable like the 125ASX and in exactly the same form factor as the ones sold now.
Hello All, Here's my 2 cents worth about the SE to BTL conversion (as I also posted on Nisbeth's slowdiyer):
Just a couple of FYIs: I just replaced a BTL version with a converted SE (just changed the W40x jumper) in my Gallien Krueger MB115 bass amp and it seems to work. Double the voltage across P104 vs. each side to Ground, but I haven’t listened to it yet or made any measurements. The W40x jumper is what reconfigures the outputs so that they both appear on P104. I don’t think it has anything to do with the sync.The only other difference I could see between the two types is that the BTL has a 560 ohm sm resistor in the middle of the group of sm components between IC400 and IC401-402 whereas the SE has a resistor which is marked with what seems like a 0 (it’s a tiny square). It also looks like the 560 ohm was hand soldered, as was the jumper .Maybe a clue about the difference.
Hope this is useful to someone.
Cheers, David
Next day:
A couple of further things: I measured the two resistors in question and they are, in fact, 0 and 560 Ohms. Also, I looked at the magnified photos of both types on eBay,etc. and they all correspond to what I saw with my two amps. At least on the top side. I couldn’t find any clear enough photos to check the back side and I already installed the converted SE amp in my bass amp and don’t feel like taking it out again (right now anyway). 🙂
Annoyingly, for me anyway, the BTL version is now widely and cheaply available (eBay, PartsExpress, etc.). I bought the SE a while ago and procrastinated installing it.
Cheers and Happy Holidays, David
Just a couple of FYIs: I just replaced a BTL version with a converted SE (just changed the W40x jumper) in my Gallien Krueger MB115 bass amp and it seems to work. Double the voltage across P104 vs. each side to Ground, but I haven’t listened to it yet or made any measurements. The W40x jumper is what reconfigures the outputs so that they both appear on P104. I don’t think it has anything to do with the sync.The only other difference I could see between the two types is that the BTL has a 560 ohm sm resistor in the middle of the group of sm components between IC400 and IC401-402 whereas the SE has a resistor which is marked with what seems like a 0 (it’s a tiny square). It also looks like the 560 ohm was hand soldered, as was the jumper .Maybe a clue about the difference.
Hope this is useful to someone.
Cheers, David
Next day:
A couple of further things: I measured the two resistors in question and they are, in fact, 0 and 560 Ohms. Also, I looked at the magnified photos of both types on eBay,etc. and they all correspond to what I saw with my two amps. At least on the top side. I couldn’t find any clear enough photos to check the back side and I already installed the converted SE amp in my bass amp and don’t feel like taking it out again (right now anyway). 🙂
Annoyingly, for me anyway, the BTL version is now widely and cheaply available (eBay, PartsExpress, etc.). I bought the SE a while ago and procrastinated installing it.
Cheers and Happy Holidays, David
Zombie thread I know but I have three SE modules. I have modified one using the 400/401 link and it worked well in a small bass combo. I have now built an extension cab and will install the other in there. I will investigate the changing the 560 ohm resistors If I can find them. I suspect they may have something to do with the sync functions.
On the transformed SE-->BTL(w40x jumper) I studied THD+N 1kHz with the resistor 0 soldered out (SE version), connected the variable resistor 0-5KOhm. By smoothly changing resistance from 0, I saw that at a value close to 560 Ohms and above, the sharpness of THD+N 1kHz(load 4 Ohm, balance input) improve from 0.01(2)% to 0.004(5)%. Further increase in resistance does not change THD+N.
I don't understand why in the photo of the factory BTL version SMD with the inscription "560" - it is 56 Ohm, but in fact it is apparently 560 Ohm (BluesAholic measured it). I install SMВ "561" = 560 Ohm in foto Attach
I don't understand why in the photo of the factory BTL version SMD with the inscription "560" - it is 56 Ohm, but in fact it is apparently 560 Ohm (BluesAholic measured it). I install SMВ "561" = 560 Ohm in foto Attach
Attachments
Just re-read this thread after all these years because I'm having a bit of trouble with my SE to BTL converted module (to be investigated).
But Rawamps comments made sense and caused me to wonder about my measurements. So I re-measured the questionable resistor and it is 56 Ohms. I used a 4 1/2 digit DMM both times and realized that my mistake was not noticing the leading zero, Bah!!
Judging from Rawamps clever trick with the pot, it doesn't seem to matter much. But I just wanted to correct my mistake for the record.
Cheers.
But Rawamps comments made sense and caused me to wonder about my measurements. So I re-measured the questionable resistor and it is 56 Ohms. I used a 4 1/2 digit DMM both times and realized that my mistake was not noticing the leading zero, Bah!!
Judging from Rawamps clever trick with the pot, it doesn't seem to matter much. But I just wanted to correct my mistake for the record.
Cheers.