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[ammitsboel]

Just saw that the calculator was for an old model with many series coupled resistors.
I would say that the L shunt type I'm doing is better.

[Level]

I built some based roughly on this model. 31 steps though.

I agree!

http://www.siteswithstyle.com/VoltSecond/12_posistion_shunt/ 12_Position_Pure_Shunt.html

[ammitsboel]

Interesting site

I'm fooling around with the thought of ordering a switch with about 56 steps...

Do you sometimes have some clicking/poping in your switch?
Mine is a shorting type and is also grounded, but i still have some clicks now and then...?

[Level]

They get that way..here is a page on that subject...

  http://www.siteswithstyle.com/VoltSecond/Popping_attenuator_ fix/Sweet_Whispers_Popping_Noise_Fix.html

I guess keeping them ruthlessly clean and lubercated..and with the ground is about all you can do.


PS, these are reported to be nice...

http://www.dact.com/html/attenuators.html

[ammitsboel]

I use these SEIDEN 45 SG:
http://www.tachyon.co.jp/%7Esichoya2/seiden/index.html

Together with 1W tantalum resistors and 4x 2W special tantalum in series pr. channel... go home DACT!...

Best Regards
H

[Level]

That 62SG looks sweet. I was going to go for some Marchands but the price put me off some...(Pic) Assembling is the only way to go.



PS, I see a pair of monos is down to 400 in kit form...Hummmmmm..

[bblackwood]

Hehe, that's actually my exact attenuator I had Phil build for my console (he liked it so much he took a pic and put it on his website).

Holcos on a Shallco switch. Will last longer than I will...

[Level]

Cool brad! Marchand offers them in kit form..I like, I like, price is decent.

[ammitsboel]

Brad how do you like the Holco's? what did you have before?

And how are the shallco's? They look a little "clonc'ish"?
The SEIDEN I'm using has the smoothest operation I've ever tried in a switch.

Best Regards

[bobkatz]

Obviously, if you are looking for exact, known steps, the value of your series resistor can be only one value, but I assume this you already know. You must be fooling with brands (Vishay, etc.).

If you're really a "1 dB/step" perfectionist, you also have to take into account the source impedance and the load impedance. I have a simple Excel spreadsheet that calculates this for an L pad type of attenuator (fixed series R, variable load R).

BK

[bobkatz]

ammitsboel wrote on Sat, 04 December 2004 14:43

Interesting site I'm fooling around with the thought of ordering a switch with about 56 steps... Do you sometimes have some clicking/poping in your switch? Mine is a shorting type and is also grounded, but i still have some clicks now and then...?

Grounded?  How?  Anyway, if you get clicks perhaps there is some dc offset in the circuit, it could pop even with a shorting switch. The life of the contacts goes downhill fast if there is dc in that part of the circuit, also.

BK

[bobkatz]

bblackwood wrote on Sat, 04 December 2004 15:15

Hehe, that's actually my exact attenuator I had Phil build for my console (he liked it so much he took a pic and put it on his website). Holcos on a Shallco switch. Will last longer than I will...

I wonder how the sonic quality of this compares with a TKD attenuator. Those TKDs are going now for over $300 (stereo). No one knows what's inside because they're too expensive to waste.

I certainly had no problems with the sonics of the TKD. How would one go about evaluating objectively the quality of an attenuator? Is it possible to measure harmonic distortion of a resistor? How do you determine the quality of switch wipers by measurement with the resistors already in place?

BK

[Level]

Bob, while we are on this subject, what do you know about these?

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2782/ln/

POS??

[bobkatz]

Level wrote on Sat, 04 December 2004 23:56

Bob, while we are on this subject, what do you know about these? http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2782/ln/ POS??

I've seen a number of variations on this scheme, including one from the Scottish IC manufacturer Wolfson (or some name like that). You can use your own (discrete if you wish) opamp with the Wolfson. The concensus amongst the golden ears is: These types of circuits have come a long way, but trust me, they are not as transparent to the ear as gold contacts and Vishay resistors!

[ammitsboel]

bobkatz wrote on Sun, 05 December 2004 17:22

Level wrote on Sat, 04 December 2004 23:56 Bob, while we are on this subject, what do you know about these? http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2782/ln/ POS?? I've seen a number of variations on this scheme, including one from the Scottish IC manufacturer Wolfson (or some name like that). You can use your own (discrete if you wish) opamp with the Wolfson. The concensus amongst the golden ears is: These types of circuits have come a long way, but trust me, they are not as transparent to the ear as gold contacts and Vishay resistors!

I have yet to try the Vishays, but right now I'm using a tantalum type witch by some people is regarded higher quality.
I've tried gold contacts but I like silver contacts better and find them more transparent.

The grounding in my switch is only the chassis.
I have no DC in my attenuator circuit.
I think the clicks is when the switch fail to short properly and the full signal reach the speakers for a very short period causing a click/pop.

Best Regards,