Thanks for the pics Michael
I haven't had time to open mine yet...so it's good to know what to expect.
Yes - the facia of the case has a strange finish to it. Mine looked perfect when it arrived - until I started to handle it. It seems to oxidise easily after human contact. A good reason to rebox it or paint it a whacky colour.
Is the board actually sagging under the weight of the inductors - or is it just squeezed into the case a bit too tight and flexing so it can fit?
I haven't had time to open mine yet...so it's good to know what to expect.
Yes - the facia of the case has a strange finish to it. Mine looked perfect when it arrived - until I started to handle it. It seems to oxidise easily after human contact. A good reason to rebox it or paint it a whacky colour.
Is the board actually sagging under the weight of the inductors - or is it just squeezed into the case a bit too tight and flexing so it can fit?
You're right about the quality.
I just got mine, ran into some problems straight off the bat. Powered it up, and I started getting smoke (and music mind you) out of the amp. Quickly turned it off.
Upon later inspection after dismantling it I found that the capacitor closest to the chip had it's plastic insulation broken so it was shorting directly with the chip. So I unsoldered the breached cap, put in another one of the same value (100uf, 16v). Powered it up again, all seems sweet. Sounds pretty good too, ableit a bit of hum, but that might be because I've got it out of it's case at the moment.
Also noticed that the poweron switch cables were not inserted all the way into the board so, it might have been shorting there aswell.
I did talked to Eric(the seller) he offered to replace it and play for the shipping aswell, so that was good of him.
The 2 caps on the bottom right hand corner of the board right above the volume pot. I take it they're input caps, on the board it's marked 3.3uf but the value of the caps is 10uf. The amp does have a bit of a turnon sound. Candidates for immediate replacement perhaps? I do them first, and bump up the 2200uf reserve capacitor first.
What is that other little chip? it's not an opamp is it?
My board is saggy too, it's not from the weight of the components, the amp is very light. It 'could' be from the way it is held in the case.
I just got mine, ran into some problems straight off the bat. Powered it up, and I started getting smoke (and music mind you) out of the amp. Quickly turned it off.
Upon later inspection after dismantling it I found that the capacitor closest to the chip had it's plastic insulation broken so it was shorting directly with the chip. So I unsoldered the breached cap, put in another one of the same value (100uf, 16v). Powered it up again, all seems sweet. Sounds pretty good too, ableit a bit of hum, but that might be because I've got it out of it's case at the moment.
Also noticed that the poweron switch cables were not inserted all the way into the board so, it might have been shorting there aswell.
I did talked to Eric(the seller) he offered to replace it and play for the shipping aswell, so that was good of him.
The 2 caps on the bottom right hand corner of the board right above the volume pot. I take it they're input caps, on the board it's marked 3.3uf but the value of the caps is 10uf. The amp does have a bit of a turnon sound. Candidates for immediate replacement perhaps? I do them first, and bump up the 2200uf reserve capacitor first.
What is that other little chip? it's not an opamp is it?
My board is saggy too, it's not from the weight of the components, the amp is very light. It 'could' be from the way it is held in the case.
Hi zBuff
Sorry to hear you had dramas with something that I have recommended - but good new that you have solved the problem and that Eric is looking after you.
The info you provided is very useful....I'll be changing some caps soon......
What are your plans for the amp....rebox....other mods?
Sorry to hear you had dramas with something that I have recommended - but good new that you have solved the problem and that Eric is looking after you.
The info you provided is very useful....I'll be changing some caps soon......
What are your plans for the amp....rebox....other mods?
Hey no problem. Would have been nice if Eric tested them before shipping, but he has been very good about the whole thing.
I'm probably just going to stick with the cap mods for a starter, once I have a closer look at the circuit at some stage (though I'm only a beginner at electronics), I'll see if I can bypass the treble and bass controls. Once I'm done there I'll probably replace the volume pot with one of those little green Jaycar ones, they've served me well in the past on my chipamps.
A recase is definitely in the works once I've got my more exotic larger caps in from overseas and I've decided what sort of connectors I'm using (building a whole system, and I've decided not to use standard consumer connectors, might go pro, either XLRs or something similar)
The thing I like about this board is that it's all thru hole components, it should be easier to mod, especially for clumsy people like me
I've been to frightened to do some of the mods to my Sonic Impact Tamp
I'm probably just going to stick with the cap mods for a starter, once I have a closer look at the circuit at some stage (though I'm only a beginner at electronics), I'll see if I can bypass the treble and bass controls. Once I'm done there I'll probably replace the volume pot with one of those little green Jaycar ones, they've served me well in the past on my chipamps.
A recase is definitely in the works once I've got my more exotic larger caps in from overseas and I've decided what sort of connectors I'm using (building a whole system, and I've decided not to use standard consumer connectors, might go pro, either XLRs or something similar)
The thing I like about this board is that it's all thru hole components, it should be easier to mod, especially for clumsy people like me
I've been to frightened to do some of the mods to my Sonic Impact Tamp
zBuff said:I'll probably replace the volume pot with one of those little green Jaycar ones, they've served me well in the past on my chipamps.
The thing I like about this board is that it's all thru hole components, it should be easier to mod, especially for clumsy people like me
Any chance you can give us the catalogue number or link to the Jaycar volume pot.....I'm really interested in something that is good and not too expensive.
Indeed - the thru hole construction suits me too. I'll definitely be doing more to this one than the SI.
What do you think of the sound compared to the SI?
CAT. NO. RP8756
10K 9MM SQUARE POTENTIOMETER LOG DOUBLE GANG (A)
CAT. NO. RP8760
50K 9MM SQUARE POTENTIOMETER LOG DOUBLE GANG (A)
There are linear pots too in those values if you're after them instead.
$5.50 AUD a piece.
The sound compared to a stock SI ? there's more bass, things are clearer, and more microdetails, but the SI amp is warmer and smoother. That was my initial impressions, can't do an A/B test as I don't have my SI t-amp on my at the moment.
10K 9MM SQUARE POTENTIOMETER LOG DOUBLE GANG (A)
CAT. NO. RP8760
50K 9MM SQUARE POTENTIOMETER LOG DOUBLE GANG (A)
There are linear pots too in those values if you're after them instead.
$5.50 AUD a piece.
The sound compared to a stock SI ? there's more bass, things are clearer, and more microdetails, but the SI amp is warmer and smoother. That was my initial impressions, can't do an A/B test as I don't have my SI t-amp on my at the moment.
I like the BOSS -pot on the front panel. What is it for?
The 8pin chip might be an opamp since it is so close to the input RCAs and most of the cheap D-class amps were meant to be driven by low-output iPods and the like.
Just a suggestion of course.
Is this amp already available through international resellers or still only from Hongkong?
The 8pin chip might be an opamp since it is so close to the input RCAs and most of the cheap D-class amps were meant to be driven by low-output iPods and the like.
Just a suggestion of course.
Is this amp already available through international resellers or still only from Hongkong?
I've been using the Lepai Tamp for a while, then I thought, gee I never did test for DC on the speaker output. So out comes the multmeter, 10mv on the right and 150mv on the left, quite a difference, is 150mv OK? Now the big shocker is when I turn the power switch off on the Tamp, the right channel is ok goes up to a spike of about 300mv, but the left channel spikes up 2.5v and then drops down to 1.5v after a little while, woah doggie, that's not good is it? I assume there must be a short somewhere on the amp but I'm not sure where. I'm wondering whether that shorted cap that was smoking on my amp when I first got it had something to do with it(I did replace the cap)?
Anyone got any ideas? or should I send it back to Eric?
Anyone got any ideas? or should I send it back to Eric?
Well, the wife was out Christmas shopping and I found myself at a loose end last night so I broke open the case for a look… …..Oh dear, what a mess!
Although there is a strange logic to the way the boards are set out. The configuration allows you to get really close to the chip and not contaminate the outputs with power lines running too close.
So out came the power caps and stiffener and in went 2 x 1000uf NIC NRSK’s and a 2200uf Pan-FM. Hmmm much better. Then I noticed there was nothing else filtering the rails so in went 2 x 0.1uf ceramics…as close to the chip pins as I could get them. Pretty difficult working on that vertical board!
Before that I did notice that Cpump had 2 caps on it? A 100uf ‘litic and a bead @ 1uf. Looking at the datasheet it calls for a 1uf only, so I removed them both and dropped in a 1uf 0805 from my Sonic modding kit!
(not sure if this was the right thing to do but I’m sure someone will put me right?)
The input section is mayhem, with opamps, bass and treble filters and coupling caps galore so I left that lot alone. It’s driving a pair of old monitors in the kitchen at the moment and the tone control is quite useful.
Left the output section alone for the moment so I can assess any improvements although I have a set of aircores that would fit nicely!
Later
Lee
…..Oh dear, what a mess! Although there is a strange logic to the way the boards are set out. The configuration allows you to get really close to the chip and not contaminate the outputs with power lines running too close.
So out came the power caps and stiffener and in went 2 x 1000uf NIC NRSK’s and a 2200uf Pan-FM. Hmmm much better. Then I noticed there was nothing else filtering the rails so in went 2 x 0.1uf ceramics…as close to the chip pins as I could get them. Pretty difficult working on that vertical board!
Before that I did notice that Cpump had 2 caps on it? A 100uf ‘litic and a bead @ 1uf. Looking at the datasheet it calls for a 1uf only, so I removed them both and dropped in a 1uf 0805 from my Sonic modding kit!
(not sure if this was the right thing to do but I’m sure someone will put me right?) The input section is mayhem, with opamps, bass and treble filters and coupling caps galore so I left that lot alone. It’s driving a pair of old monitors in the kitchen at the moment and the tone control is quite useful.
Left the output section alone for the moment so I can assess any improvements although I have a set of aircores that would fit nicely!
Later
Lee
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panomaniac said:
Hi Michael, there is certainly an improvement in noise reduction! I hooked it up to my fullrangers last thing and it has lost all that hiss and hum.
It was too late to start lifting the volume so I'll do my full assessment this evening.
I still need to put a DC null circuit in there as well.
Not sure about touching any of that input section sir...I'll let the experts decide what goes and what stays! I would just bypass the lot and go straight to the chip pins but the tone control is too useful at the moment.
TTFN
Lee
Look Out!!!!
Hi chaps, I forgot to mention on my last post that there are issues with grounding on these amps!!!
When I took the PCB out of my case I noticed there was no insulation between the chip and the case so even if you are not going to modify it at least put some insulation in there
But…worse than that! Last night I had it linked to my CDP and picked it up…Hummmmmmm… Ah! The case is still grounded, probably by the pots on the front panel but you never know.
I then inadvertently put it down on my main amp which has a safety ground to its metal case……
THUD!!!
The blue fault LED came on for a brief second and the amp went into protection mode!
I had to disconnect the power cord to reset the amp (the switch on the front is just a mute). After that it was fine again but whatever you do, don’t earth the case!!!
I’m going to completely isolate the damn thing so this can’t happen again……..
Oh yes, and whilst I’m on the subject…I plugged in a floating source (MP3) and you get a hummmmmmm when it’s between tracks or not playing. This is easily remedied by earthing the ground lead on your interconnect.
Hi chaps, I forgot to mention on my last post that there are issues with grounding on these amps!!!
When I took the PCB out of my case I noticed there was no insulation between the chip and the case so even if you are not going to modify it at least put some insulation in there
But…worse than that! Last night I had it linked to my CDP and picked it up…Hummmmmmm… Ah! The case is still grounded, probably by the pots on the front panel but you never know.
I then inadvertently put it down on my main amp which has a safety ground to its metal case……
THUD!!!
The blue fault LED came on for a brief second and the amp went into protection mode!
I had to disconnect the power cord to reset the amp (the switch on the front is just a mute). After that it was fine again but whatever you do, don’t earth the case!!!
I’m going to completely isolate the damn thing so this can’t happen again……..
Oh yes, and whilst I’m on the subject…I plugged in a floating source (MP3) and you get a hummmmmmm when it’s between tracks or not playing. This is easily remedied by earthing the ground lead on your interconnect.
Attachments
Oh yes...and I think this amp sounds very good now, with 'boss' and treble wide open it reminds me of a modified Sonic, (a stark black background and 'haunting' mid/highs) not as smooth as an amp6 or Charlize...... but I bet that's the inductors talking ....and all those 'litics in the signal path
Definately a good alternative to an over priced Sonic impact (in Europe anyway)
Nice one Fin
Lee
....and all those 'litics in the signal path Definately a good alternative to an over priced Sonic impact (in Europe anyway)
Nice one Fin
Lee
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