[tom hankins]

Quote:

Originally Posted by darkclouds The problem, as I see it, with a disorganized and haphazzard layout like the one in the pics is standardization. It'd be pretty hard to make each amp as close to the next if the layout aren't the same.

According to the reviews, and feedback from the meets, this has not been a problem with the amps. The amps tend to get very good consistent reviews from where ever they are heard. Going by all the positive feedback as to the sonic quality of the amps I would say they are very consistent as far as sound quality goes.

 

[ReDVsion]

Coming in late here; is this all about disorganized internals or some other deeper problem (bad soldering job, whatever)?

 

[cosmopragma]

Quote:

Originally Posted by PinkFloyd OK, from what I have seen from the pics I say "I wouldn't buy one of those amps...... EVER" Is that conclusive enough? EDIT: I wouldn't buy purely on safety reasons.

Ditto.
I'm in the market for a tube amp and I was tempted by Singlepower's approach of building amps suited to individual requirements.
A tube amp has to be warmed up and I just don't have the time to sit there patiently with a bucket full of sand in my hands watching the amp warming up.
In case the amp blows and the house I'm living in burns down my fire insurance won't pay.I would be ruined for life.
Someone asked if there are tube amps meeting the basic security requirements of the CE regulation.
At least the Audio Valve RKV and some Antique Sound Labs amps are CE approved.

 

[gsferrari]

[size=small]SINGLEPOWER PACKING :[/size] (specific to these videos and in this case - Mikhail flew into florida with the amplifiers)

This is just a cardboard box. No crate - but a VERY stiff and strong cardboard box and layer upon layer of bubblewrap.

Nothings gonna break in there...add a crate and this is the next generation US Army tank!!

[size=x-large]VIDEOS :[/size]

Video #1

Video #2

Video #3

 

[jude]

I'll let gsferrari's packing videos stay, but no more comments on packing. Stay on topic, folks.

 

[Sovkiller]

Quote:

Originally Posted by Mastergill One last for me. I think the few pics posted are not enough to make a valid judgement. It can be a prototype, a demo stuff, we need pics of the whole thing from a recent product. However seeing how it is difficult to obtain those damn pics, this is very very suspicious to say the least.

This was discussed already on page 1...

Quote:

Originally Posted by Tuberoller I have nothing to say about the pictures posted here. I can say that the seven other Singlepower amps I have opened(four of the older models and three more recent models) have all looked very similar in build and layout to this amp. I cannot post my pictures due to possible liability.

 

[rickcr42]

OK,on topic question.Who here that has ever weilded a soldering iron or has updated the parts of an amp or CD player would be looking forward to messing with for instance the orange drop caps shown here :

I count four connections that would need to be cut or at the minimum desoldered in order to free up the two caps.And I personally see no way to get the caps off the terminal without removing everything.
yes this is an attempt at star grounding but there are times when global star grounds make more sense , for instance when the layout becomes unweildy,too many connestions go to one point and a cold solder joint would be hard to find in a "mass" of connections.If i were going to go the single point ground route i would use a teminal with multiple tie point and daisy chain them.This can be considered taboo by some due to the impedance differences between the ground points but works fine in practice.

pray one of those rectifiers never fail from a surge or you are looking at replacing caps,rectifiers,wiring,more caps...
all twisted together and then soldered as a group.


Long term reliability ? Who knows ,but what happens ten years down the road and this puppy needs servicing.If no schematic is availble and singlpower is no longer in business what do you do ? Try to trace out the circuit in that ?
Yes it can be done but remember-most audio servicing runs around $80/hr.
It adds up damn fast and there comes a time with gear,not this piece necessarily but any gear,where the returns are not worth the effort and cost to repair/update.I would not personally spend $500 to "fix" a $200 amp as an example.

I am not picking on the amp or the amps designer and i have as stated before never heard the amp itself.There seems to be many fans of the amp and that is also fine.they payed thier money for what they wanted and no one can knock another persons personal preferenc.If we all wanted the same thing then there would only be a need for a single amp design.
I am just voicing my personal concerns about the layout which seems to be alarming to not just me but many others,some afraid to say anything.even with a schematic it is not something i would relish digging into and if one came into my possesion i would address this.Problem is,because of the amount of multiple tie points and twisted together parts,any modification would mean an entire rebuild and rewire since no one part can be removed without also removing its brother and sisters.
And the amp is not among any of the amps i have seen the "undies" of that i consider to have a clean layout.A servicing nightmare at best unless sent back to the factory and modifications/upgrades are out for the meek of heart and those lacking in much free time.as for relaibility..

A certain percentage of amps will break down at some point.there is no such thing as 100% reliability and even QC misses things

Just my opinion and not directed at any one person or group but someone had to say these things that some wanted answered even though not wanting to ask.not slamming the amp just saying i would not want it without an entire rewiring and more tie points for the passive parts

 

[kevin gilmore]

I'll just add that all electrolytic caps dry out over time. Every one of
them no matter how expensive. About 12 years average, as little as
5 years at elevated temperatures.

 

[Wodgy]

Rickcr42, do you think there's a cold solder joint near the top of the second picture you posted? (Near the red wire.) Both of the solder joints at that position look like they could be cold. I'd be concerned about one of them coming loose.

 

[PhilS]

Quote:

Originally Posted by archosman Ok... I figured an impartial jury would be best. I have an on-staff engineer as well as an editor who used to be an engineer about 15 years ago. Yesterday I showed them the pics that were posted. They were concerned with quite a few things that they saw which I won't go in to.

Oh, that's helpful. Once again, can somebody be specific, like rickcr42's post?

P.S. I talked to an engineer friend of mine and he said there was nothing to worry about. Can't go into it though.

 

[darkclouds]

Believe it or not, you don't need to be an engineer to recognize well thought out and planned out work that require meticulous attention to detail. Then again, you don't need to know much to recognize a hornet's nest either.

 

[braillediver]

A friend recently bought an MPX3 this is his feelings on the issue.

“i really don't understand why this QA issue hasn't come up before with the singlepower amps. checking out the innards of an amp is pretty standard. from the looks of it the mpx3 is on par with the asl line in terms of build quality. i have lost a lot of respect for the so called amp gurus on this web site who have pushed the singlepower line so much. they are basically fanboys who have lost all rational thought. i can't believe that these so called hifi amp experts weren't curious enough to open it up to see what made it tick! the famous 6moons review is basically a shill for the singlepower line as well, that's the only way i can explain why he didn't mention anything about the internal wiring. he only gave some half assed explanation about why he couldn't publish any internal pictures.”

Love them if you want but some people expect more for their hard earned money. It speaks volumes that we haven’t heard anything from the manufacturer explaining his assembly practices.

From the photos how can any 2 amps be the same?

How can there be any consistency from unit to unit if it’s just a jumbled mess of parts?

I’ll get to open and photograph an MPX3 this weekend and I’ll post the pictures to enable free and open discussion of the issues.

Manufacturers have established certain reliable assembly practices to ensure a consistent and reliable product. This amp doesn’t show any of those successful time-tested practices.


Mitch

 

[rickcr42]

Quote:

Rickcr42, do you think there's a cold solder joint near the top of the second picture you posted? (Near the red wire.) Both of the solder joints at that position look like they could be cold. I'd be concerned about one of them coming loose.

i will not comment on if there is or is not a cold solder joint present because i don't want to crap on the product.but instead I can tell you what one IS and why it is bad.

First of all,it has nothing to do with strength so a part coming loose from a cold joint is not something to worry about unless an extreme case and that would never make it out the door.
When you solder a part you do not apply heat directly to the solder but instead to the part being soldered and the solder is applied to the opposite side of the part .
The heat transfer from the iron to the part once at the flow temp of the solder will allow the solder to FLOW around the part and make a secure connection.Fail to use a how enough soldering iron or use a solder with too high a melting point for the job and in order to get the solder to flow you are sometimes on the part with heat for too long and damage of the part can result.
So good flow in a reasonably fast time period is essential.

But if you do not apply the heat long enough,you remove the iron too soon,or if the part moves even a tiny little bit before the solder cools you will get a cold solder joint

so too much heat damages parts,too little makes a bad joint.

what a cold solder joint is : instead of a solid mass covering the entire area of the part and connection the solder crystallises

Solid mass+good low inpedance connection and good signal integrity

Crystalized solder=high impedance connection and a very poor electrical connection.The part will actually think a resistor is between it and the connection point.NOT Good !

Cold solder joints in extreme case can be so high in impedance it will actually act as a radio receiver !

the old RFI thingy.

what may sound like background noise and hiss,crackles,etc may be no more than a cold joint picking up RFI.

OK. So how do you identify a cold joint ?

The easy way is to look for dull solder.This is the normal giveaway.but not all dull joints are "cold" and not all shiny joints are good !

I know,confusing.but there are NO absolutes here.

some dull appearing joints actually cooled fine inside and maybe a draft hit the joint (blow on hot solder and see what happens-it gets dull !).

Some shiny joints if there are too many metal parts connected together and all cooling at different time intervals because of dissimiliar materials may be a damn cavity fest internally (another reason i personally do not attach too much to one single point)

One looks bad and is good,one looks good and is bad !

and that is why troubleshooting a project can be so damn agravating at times !

It SHOULD work but it don't ! grumble grumble grumble

time to track the problem down and the cleaner the layout,the more "intuitive the design groups the easier it will be to fix.

again,i am not picking on this particular amp,just schoolin' you youngsters on what can and does go wrong and why.Even non DIY folks should KNOW a thing even if they never put it into practice

rickster

 

[Wodgy]

Rick, I've built enough amps to know that cold solder joints are almost always the ones that come loose when something is pulled or shaken. This isn't just my experience. Over at the Bottlehead forum, the first thing the Doc blames when things come loose is a cold solder joint.

 

[rsaavedra]

Thanks for a very useful post Rick!