• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Group order of switched ladder attenuator? Anyone interested?

Status
Not open for further replies.
Jump to Latest
#81
Below is a picture of a balanced-8-layers-10K-24 Steps-attenuator that I bought recently ... you know where from. Temporary installed at the back before I get a new chassis. It sounds fine to me and it's well worth the $90.
 

Attachments

  • bosoz with 24 steps 10k balance attenuator 013.jpg
    bosoz with 24 steps 10k balance attenuator 013.jpg
    59.5 KB · Views: 705
#85
I assembled one channel of the ladder attenuator today. It is quite a difficult task, as there are 46 resistors per channel to put in place and solder. It took me about 2 hours to get the single channel put together, soldering one row at a time. This time includes the time that I spent sorting out the resistors.

I am worried that this is too tedious of a task for most people to do. What does everyone else think?

Besides the ladder attenuator, here are the other options (all 2-channel stereo units):
1. Series attenuator: half the resistors, much easier to assemble, since 1 channel = 1 deck. The price is a good deal less, probably $60 with resistors. (requires assembly)
2. DACT series attenuator, preassembled with SMD resistors. This unit has gotten great reviews, and will probably cost around $105-$110. This is fully assembled and working.
3. Goldpoint Mini-L ladder: This unit is easier to assemble, since the 2 decks are assembled seperately. I haven't determined the pricing yet for these units, but they will probably cost more than the DACT units for a stereo ladder attenuator, including resistors (Dale RN60D)

I am thinking that for the convenience and great price break for 50 units, the DACT unit would be the best choice.

Here is a picture of the my unit, half assembled:

--
Brian
 

Attachments

  • switch.jpg
    switch.jpg
    61.7 KB · Views: 652
#91
How about shunt-type? It also has only 2 resistors in signal path. It's impedance is varying a little, but for example with 10kOhm series resistor it's input impedance with 20dB attenuation is still only 11.1kOhm. And with more than 30dB attenuation it is practically equal to ladder type.

With shunt type you need only half the parts compared to ladder, and only one switch connection per channel. Is the ladder really worth double the parts and extra switch connection in signal path?
 
#93
tmj said:
Is the ladder really worth double the parts and extra switch connection in signal path?
Click to expand...

Probably not😉

What I already proposed to Brian is a modified ladder, which sort of rides on simplicity of fixed series/variable shunt, yet provides more flexibility than a simple series/shunt single deck attenuator (less variable resistance and no gain loss at max setting).

A four deck switch has to be used, but with less resistors, as if you noticed the series resistors values are repeated through various settings, so why using them every time?

Instead of 23 series resistors, you
only need 5 (a better type), as all other are quite close in values. Shunt resistors values have to be recalculated for correct attenuation (the number of
shunt resistors stays the same), but I don't see a reason why this wouldn't
work and why nobody's using that setup. Why using 23
resistors, if 5 is more than enough? Of course 2k difference in total
resistance is not a problem, unless some accurate filters are used at the
input..
 

Attachments

  • ladd1.jpg
    ladd1.jpg
    12.8 KB · Views: 830
#95
Anyone want to take on this group order? I have ordered the parts for the next batch of pcb/kit orders for the gainclone boards, and don't have the finances/resources to do both the attenuators and gainclone kits. If someone wants to take over this group order, it would be quite helpful for me. Otherwise, I can do it farther down the road, after I get the other stuff taken care of.

I can help out with the order page/paypal shopping cart setup for this order if someone wants to do this.

--
Brian
 
#99
Hi,

I sure hope so, I'm still interested, but I think BrianGT is still busy with
other group orders, and since he's the once that started this thread...

What's the resistance value of the $95 one? The Elma switch alone
will cost me about €97 here in Holland, so $95 is not bad (I assume it's
including the resistors).

Greetings,
Ray.
 
#100
6h5c said:
Hi,

I sure hope so, I'm still interested, but I think BrianGT is still busy with
other group orders, and since he's the once that started this thread...

What's the resistance value of the $95 one? The Elma switch alone
will cost me about €97 here in Holland, so $95 is not bad (I assume it's
including the resistors).

Greetings,
Ray.
Click to expand...

Yeah, I don't have time to do an order of them. They come out to around $70 each without resistors if a big enough order is created, direct from Elma.

I would rather go with the series attenuator units, as they are much, much easier to assemble, and cost quite a lot less, around $40 each.

--
Brian
 
Status
Not open for further replies.
Top Bottom