|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
190.163.28.94
hello,
I like to know if there is any "hidden" disadvantage on use a ladder stepped attenuator vs a series stepped att. I mean, it is an obvious thing that on ladder type there is only 2 resistors + 2 contacts through the signal path on each channel and on the series there are 42 (evaluating to get a 41 steps att.) resistors + 1 contact on each channel across the signal path. Both types preserve the impedance.
The Ladder use 1% metal resistors and silver contacts, series use non-inductive SMD resistors and silver contacts.
From the sound point of view, one might think that the ladder type, due to have less components on the signal path sounds more pure, but have the double of all mechanical parts and a good rule almost always is "keep it simple". On the other hand, if the SMD resistors are transparent enough maybe there is not that big sonic difference. I am only guessing as I have never used one of this. So I will appreciate a lot any comments from those who have had experience with both types. The cost is no object for one of this two options. Please don't offer me other possibilities; I would like to evaluate only this two.
Best regards
Follow Ups:
Series ladders are easier to break in; set at lowest level and play. The two resistor elements must be broken in at every step separately.
hello unclestu, thanks for your answer.
good point.
besides the break in, you prefers ladder or series at the end of the day?
regards
Cj uses a system which used 13 resistors in series and parallel to get 100 positions. but like a series stepped attenuator, a click one way or another and the sound changed dramatically. Drove me nuts. I ran it one full day (24 hr in the lowest position and another in the next up position up. That helped considerably.
you can get these attenuators on a chipset now. The issue becomes, on high volume inputs you can overload the miniature devices, SMD like.
I like the use of larger resistors. There is no chance of overloading them. That being said, it depends on the input device you use,7. I have successfully used the DAC volume controls and liked them. SMD's do sound different....
1/4 watt isn't large enough? What next? 1/2 watt?
And the stepper I looked at? A series of resistors, or rather resistors in series, with a variable tap. All the current is divided thru ALL the resistors ALL the time.
And for my application, the 24 step version is PLENTY.
It is ALSO a make before break style switch so NO chance of clicks / pops.
Too much is never enough
used an older Theta DAC once: 7 volt + output: overloaded many stepped attenuators
Edits: 08/14/15
How did the overload express itself?
Any chance it was the NEXT input stage which overloaded?
Too much is never enough
distortion at the louder music volumes.
IIRC it was an early issue with ARC preamps using opamp volume controls too.
and that's depends on which stage is placed the attenuator or volume control, I guess.
My SET300B integrated has the control between the first(input tube) and the second stage (driver tubes).
Btw, when you said larger resistors you mean 1w? 2w?
And what's wrong with the ladder attenuators, besides the complex break in?
regards
p.s. my digital source (Sony DVPNS999ES) output voltage is: 2 Vrms/10 kilohms
My connect at Parasound tells me with great authority that to replace the level pot, I need ONLY to use 1/4 watt resistors in a voltage divider net. I suspect that the GoldPoint series attenuator with 1/4 resistors (surface mount) would work Just Fine. The pair of resistors as a divider is if I have decided on the level and don't intend to mess with it.
A level control with 1w or 2w resistors? Pretty darn beefy. In that case I'd be tempted to measure the variable and replace with a divider OR simply modify the circuit for less gain. I don't know enough electronics to figure where such a major device would be of use. Except maybe as a speaker 'L' pad.
Isn't 2v output 'typical'?
Too much is never enough
There has been about a decade now of complaints against how SMD resistors sound on these attenuators. The most recent complaint that I read had the OP preferring a $5 carbon pot to a rather expensive SMD attenuator.
It was apparently drastic enough that on two otherwise identical amplifiers, the stepped attenuator made one sound broken.
I have not had a smd type before and was wondering what the difference was.
Hello Caucasian Blackplate,thanks for answer.
the ladder att. in question uses metal film resistors(1%). The series att. uses SMD....are all smd resistors the same? goldpoint stopped to make the ladder att. because, as they claim, that found a good transparent SMD resistors that can match the quality of a good ladder attenuator with only 2 resistors in the signal.
regards
The Goldpoint is the very attenuator to which I was referring.
and all SMD are made the same bad sound?
what's about a ladder attenuator with metal film resistors?
I'm not intended to buy a golpoint by the way, but an Acoustic Dimension.
regards
No they don't all sound the same. Problem is AFAIK the better-sounding SMD ones are rather expensive, and don't come all in one package for a stepped atten. IOW there'd be no advantage to using them, manufacturing cost-wise, and in fact they'd cost a lot more than using "regular" resistors. I suppose there could be some savings in that a machine could quickly assemble the SMD atten, but it wouldn't be smaller either, as the quality-sounding SMDs I'm thinking of are not small (components that sound good rarely/never are).
All I'm doing is opposing the inference that all SMD resistors sound bad, not offering solutions.
That's good information to hear. I'm guessing you're referring to the bulk foil surface mount parts sound a little better?
I had also been wondering if the lack of a mechanical connection might've had something to do with it.
cfraser,
thanks for your answer.
well, I was guessing exactly that.
btw, it is very strange that there is no consensus at all regarding attenuators, no matter there are objective aspects to judge them.
regards
Upsides: The input impedance is constant no matter the attenuator position
Downsides: when you are switching the output goes open circuit briefly. This can create problems downstream depending upon what you are feeding with it. Anything mitigating this might have a sonic signature (such as having a make-before-break switch, or a brief mute), and doing nothing will have a sonic signature (perhaps a popping or clicking sound)
It is more complicated than other topologies requiring nearly twice as many resistors.
There is nothing magic about it, really. With a buffer circuit the changing impedance of a series attenuator is mitigated entirely (it isn't the number of components, but the changing impedance that might have any kind of sonic impact)
If you are trying to design a passive preamp, I'd likely go with the ladder network. But I'd try to control the impedance between resistors (say a large value resistor to keep it from going entirely open circuit?)
============================
As audiophiles, we take what's obsolete, make it beautiful, and keep it forever.
Hey! I have a blog now: http://mancave-stereo.blogspot.com or "like" us at https://www.facebook.com/mancave.stereo
hello bromo33333,
thanks for your answer. I believe that you put a big pint here.
"If you are trying to design a passive preamp, I'd likely go with the ladder network. But I'd try to control the impedance between resistors (say a large value resistor to keep it from going entirely open circuit?)".
So depends on the design to minimize the noise?
The series att. from this company, is very good according to the reviews, maybe almost as good as the ladder, but I never seen a review about the ladder model. If depends on the careful selection of the resistors, maybe the ladder can offer a true improvement. I can pay a little more, but I don't want to do it if there is a noisy behaviour that can be annoying.
regrds
.
The most common downside with ladder attenuators is audible "snaps" when transitioning from one level to the next. Devices that are sensitive to momentary impedance changes, these transitions can get quite loud. (The problem can be exacerbated if you tend to turn the volume knob slowly.)
This is the main reason why ladder attenuators haven't been more common. It's otherwise the ideal attenuator type.
Hi Todd,
thanks for your answer.
And this noise problem happens regardless how well is designed or the quality of the switch?
regards
since the way that the contacts (input - output) this designer varies the common design to get a better contact. Maybe this can reduce also a bit the problem (from AD web site):
"Not commonly known, but in available attenuators the switching action in fact consists of two separate pressure contacts. A pressure contact from outer ring (input) to the whipper and from whipper to the inner ring (output).
After the example of high current rheostats, we have replaced the pressure contact from whipper to output with a fixed flexible wire. This is a labor extensive solution, but results in a much more open, transparent and stable attenuator. "
I have no such issue w/my Placette and it is not made w/SMD.
E
T
What difference does that make?
R.
Resistor quality makes quite a difference with SMD being inferior. The Placette uses very nice Vishay S-102 resistors. Please tell me you're not gong to say a resistor is a resistor or that an SMD soldered on a pad on a PCB is as good as a point to point wired through hole.
E
T
"Resistor quality makes quite a difference with SMD being inferior."
In what manner? I've used both over the years in various things and believe that they are largely the same given the same ilk of resistive element. There are some general differences between the two packages however namely leaded devices are apt to have more inductance while SMT packages are more likely to be flexure sensitive.
Now take your example: "Please tell me you're not gong to say a resistor is a resistor or that an SMD soldered on a pad on a PCB is as good as a point to point wired through hole."
You've convolved too many variables. If you really want to check it out fairly, try both styles in the same application. If you are soldering the leaded resistors to switch terminals tack some wires onto the SMT device and do it the same way. Likewise using them on PCB's, solder them to the same pads. And be certain that the resistive element is the same material and style, metal film I presume since it has far less excess noise than carbon.
73, Rick
awe-d-o-file,
the ladder that I'm evaluating use 1% metal film resistors. The series use SMD. I am assuming that your preamp has a ladder type, right?
Yes the linestage I use (I don't like to call passives preamps since they don't amplify) is a resistor ladder. 127 volume positions.
E
T
Edits: 08/14/15
Look at the GoldPoint materials. They may shed some light on your problem.
Also, I'd only compare LIKE to LIKE with the difference only being series VS ladder construction. All other parameters, like contact type and resistor type should be the SAME.
Too much is never enough
hi pictureguy,
thanks for your answer.
that was the first place that I have looked, but I'm not sure if they stopped the ladder production because of the cost of doing a good one and the problems to sell at a higher cost or only because the better sound is only marginal (not noticiable). There are others that still think that is the best option, like here: http://diyaudio.co.kr/wwwboard1/data/board1/compare.pdf
I don't want guide my decision on vendors comments,so that's why I am asking for comments of mates that have experienced both kinds.
regards
Edits: 08/13/15
High End Audio is one of those places in which Zero-> Imaginary improvement is still a Cost-No-Object proposition. So No, if somebody STOPPED making a 'Ladder Type' attenuator, it is probably NOT for the reason you cite. Maybe it was just too complex and less reliable? Though this IS just a switch, when all is said and done.
ME? Just conceptually, I'll go with Series and not get wrapped around the Axle. Less complexity. Fewer resistors. Constant impedance to the source. Using a good MAKE before BREAK switch with Premium parts, what's NOT to like?
What got me investigating this was my urge to REMOVE the input attenuator pots on my Amplifiers. They are Parasound A23. Replacing them with attenuators, will Definitely be a Step Up. At about 200$ per amp? (Knobs EXTRA!) It BETTER be a help!
Too much is never enough
Why not just measure the pots and replace them with fixed resistors?
-reub
hello reuben,
can you elaborate a little more, please?
regrds
Adjust the pots to your favorite setting, remove them and measure the resistance from the wiper to both ends, and use the nearest value fixed resistors instead of the pot.
-reub
That would remove flexibility BUT even the Best 0.5% resistors possible won't be NEAR the cost of a rotary switch. And this approach was ALSO suggested by Parasound!
Too much is never enough
hi pictureguy,
well that is what I'm looking for. Is common sense to think that more parts, more moving parts, add more probabilities to fail in the long term. Also, what I'm trying to determine the relation as the cost involved in doubling the decks and resistors is not proportional to the improvement in sound. How much improvement was the matter.
Regards
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: