GroupDIY

Marketplace => Black Market => Topic started by: avdo on December 15, 2015, 04:29:32 AM

Title: FS: T-PAD attenuator 600ohm from Avdo!
Post by: avdo on December 15, 2015, 04:29:32 AM
Hello fellows!
Was looking for T-pad attenuator with cheaper price for my DIY!
Only one manufactory created it for me! 
Second part of this (1Kohm) are logarithmic. First and third are linear (500Ohm each).
Today I have cheaper T-Pad with high quality for my preamp line!
You can see some photos! Prece 7$ per ps! Hope it will good and for you)))

https://www.dropbox.com/s/k6gy1s85xld9bgg/20151215_010538.jpg?dl=0
https://www.dropbox.com/s/hph5z24biqm1at6/20151215_010559.jpg?dl=0
https://www.dropbox.com/s/fn8d7u32gdlysxx/20151215_010621.jpg?dl=0
https://www.dropbox.com/s/fhxgfkc1qq8lk5y/20151215_010637.jpg?dl=0
https://www.dropbox.com/s/w77cdx5u37ytiyu/20151215_010649.jpg?dl=0

Will wait your comments!  :)
From 5 ps will be free shipping with tracking nomber.
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: EmRR on December 15, 2015, 01:00:51 PM
please put your location in your user ID.
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on December 16, 2015, 06:42:44 AM
please put your location in your user ID.
Please, check!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on December 18, 2015, 08:43:35 AM
Send to all who asked me about sample.
Please, check your mail. Track Number I sent there!

If somebody want to receive sample, ask me!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ilfungo on December 28, 2015, 01:00:50 PM
How much shippig to Italy?
Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on December 30, 2015, 07:42:37 AM
How much shippig to Italy?
Thanks!
If you will order 5ps and more - it will be free shipping for you.
If you want to buy less 5ps, shipping cost will be around 8-10 dollars.

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ilfungo on December 30, 2015, 06:17:44 PM
Thanks avdo
 I want to bus 5 tpad can Mou send me your paypal address?
How them perform?
Have your tested them in something like 1176?
Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 01, 2016, 07:27:00 AM
ilfungo, hello!
I tested it just in balanced input, I dont have 1176, but my friend, use it in 1176, and he like how does it works!
I use it today in my preamps. In the future I will planning to do and 1176.
I if you have any qestions, please, send me!
If want to receive sample, I can send to you it free!
Some boys who asked about samples, received it. Hope they will write his testing info here!
Hope all understand me, we wait!)))))

Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: andre tchmil on January 01, 2016, 08:09:27 AM
I received two pieces.
Build quality seems good , and the action feels pro.
I will test them soon.

Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 07, 2016, 02:21:52 PM
Hello guys!
Have sent yesterday all orders, please, chech your mails and accounts, track numbers are there!

Thanks to all!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: toneboner on January 17, 2016, 07:28:28 AM
Received mine yesterday, Thanks Avdo!!!  These look fantastic,, gonna spend some time tomorrow fitting them into APIs.  Will report back ...
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 19, 2016, 08:57:19 AM
Received mine yesterday, Thanks Avdo!!!  These look fantastic,, gonna spend some time tomorrow fitting them into APIs.  Will report back ...

Thanks! Will wait your report!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: mjrippe on January 19, 2016, 12:42:50 PM
Would love to hear some reviews.  I am considering ordering a few!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: Rocinante on January 19, 2016, 06:54:18 PM
Same hear.
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 20, 2016, 10:21:59 AM
Nobody wants to tell)))
Some peplies receive it twice - samples and than order.
But don't want to tell something!

We also wait, guys!

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: andre tchmil on January 20, 2016, 02:00:21 PM
Nobody wants to tell)))
Some peplies receive it twice - samples and than order.
But don't want to tell something!

We also wait, guys!

Thanks!

I hear you.
Haven't had the time to use them in a project but like I said before , the action feels good so I don't expect any troubles from this pot.
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ruffrecords on January 21, 2016, 02:13:15 PM
I just built one of these up. The plan was to arrange it so there was no attenuation when the control is fully clockwise and full attenuation when it is v counter-clockwise. Attached is the schematic I used. Unfortunately it does not work as planned. The attenuation at the mid point ought to be about 16dB but it is about 4dB. On investigation it looks like the 1K log pot has been fitted on backwards so it operates like an anti-log pot.

Thoughts?

Cheers

Ian
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 21, 2016, 04:39:19 PM
Ian, hello!
Thanks you for report, but I don't know how it be work in your schematic. You write U-Pad, but It is T-Pad!
I add the schematic for connection!

(http://groupdiy.com/gallery/0/57038-210116163607.jpeg)
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: EmRR on January 21, 2016, 04:47:59 PM
Everything sold today as a T-pad has something around a dB loss as minimum.  These, CAPI and Hairball.   Purple Audio pioneered the current recipe for their 1176, and decided it was the best course of action.  If you want a true T-pad, the shunt has to fully disconnect, and they are a special taper that maxes out at about 5K before going open at the end. 
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ruffrecords on January 21, 2016, 05:46:46 PM
Ian, hello!
Thanks you for report, but I don't know how it be work in your schematic. You write U-Pad, but It is T-Pad!


 I understand that, but wired as a T pad there is still the same problem. At the half way piont, the 1K pot is about 800 ohms so the attenuation is very little. I think the 1K needs to be log so it is 200 or 100 ohms at the half way point.

Cheers

Ian
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 21, 2016, 05:53:58 PM
Ian,
How do you test it?
I can't understand what do you do!?

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: EmRR on January 21, 2016, 06:38:24 PM
I too am confused about what you are doing Ian.  Is it loaded 600 ohms resistive?  That makes an enormous difference in the attenuation amount for given rotation. 

You want 200 instead of 800 at the half point, connect the - leg to the opposite end.  Right?  What am I missing?   The throw is going to be off for any made with off the shelf wafer tapers. 

Perhaps someone has one of these and a Hairball/CAPI and can compare 50% rotation resistances.   

If you want a true T-pad, vintage used is the only option in a continual rotation part. 


Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ruffrecords on January 21, 2016, 07:10:59 PM
OK, I see there is some confusion. I am feeding it from a transformer output and loading it with a bridging input. So the driving impedance is relatively low and the load impedance is relatively high. Even loaded with 600 ohms, the attenuation is only 6dB at the mid point because the 1K pot is effectively a rev log.

Cheers

Ian
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 22, 2016, 02:36:22 AM
Ian,
The task was to achieve a smooth attenuation of the signal.
This makes it. I really don't understand why you decided that half of it should be how many decibels!?
I think for the price it works quite well! Maybe his work doesn't meet your any desires!
The most important thing in his work is that he not spoil the sound!

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ruffrecords on January 22, 2016, 06:14:57 AM
Ian,
The task was to achieve a smooth attenuation of the signal.

That is what I am saying. It does not achieve a smooth attenuation of signal. In the first half turn you get only 6dB of attenuation. Normal attenuators will give you 14dB to 20dB of attenuation at the mid point.

Also, I think the reason is that the 1K log pot has been fitted in backwards so it operates like a reverse log pot. I am suggesting there has been an assembly error.

Cheers

Ian
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 22, 2016, 07:44:33 AM
Ian,
Can you show how do you do this test?

I don't see this when I use it. May be, if you used others T-Pad, may be there is the same about you tell!
You want to tell that I need to flip 1K resistor?

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ruffrecords on January 22, 2016, 10:57:37 AM
Ian,
Can you show how do you do this test?

Attached is a schematic of your T pad at the mid point. R1 and R2 are the two 500ohm pots, each at 250 ohms. R3 is the 1K pot which measures 800 ohms at the mid point. R4 is the 600 ohm load. V1 is the source signal which has a source impedance of 150 ohms. Under these conditions, the attenuation is only 7dB. If the 1K pot was a proper LOG type it would be 200 ohms at the mid point. This gives an attenuation of 11dB at the mid point. This is still too little in my view but it is better than 7dB.

Now, my only assumption is that with the control fully clockwise, you want no attenuation and you want the attenuation to increase and the signal to decrease as you turn it anti-clockwise.

Cheers

Ian

P.S. and if the log pot is 100 ohms at the mid point, which is what I would consider to be normal, the attenuation at the mid point is 14dB which is about right for audio use.
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 22, 2016, 02:49:50 PM
Ian,
I have tested T-Pat from CAPI,
It not has the same characteristics that you write here.
I can't understand what do you use for testing.
When I did it, I used t-pad calculator. All steps we checked and created a table.
I had 3 times of t-pad, checked all this, and choosed last t-pad.
I use it, my friends use it. And we don't have any problems with this!

If you some special t-pad, that you want, we can produce it for you. Are you realy planing to buy it?

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: envelope on January 22, 2016, 03:05:33 PM
Hello AVDO

what is the tolerance of the 3 wafers?

Thank You
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: Dreams on January 22, 2016, 03:17:54 PM
What Ian says makes sense, mechanically. Look at the pictures. The middle wafer (assuming it to be 1k) is physically reversed in relation to the other two. If someone spec'd a 1k log, and then it was flipped over, wouldn't that make a rev log?
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 22, 2016, 03:28:41 PM
Hello AVDO

what is the tolerance of the 3 wafers?

Thank You

(Total Resistance Tolerance)  ±20% ( More than 1 M Ω ±30%) - In my datasheet

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: envelope on January 22, 2016, 03:48:27 PM
thanks. Can you confirm that the middle wafer is in fact a true Log Taper.

At 50% rotation, a 1K Log taper will measure 10% of total resistance, i.e. 100 Ohms.

with +/-20% tolerance, your part should measure between 80 Ohms and 120 Ohms.

is this the case?

Also (attached is a 'generic' taper graph.)

is it possible to post a similar graph using your new part?
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 22, 2016, 04:06:21 PM
thanks. Can you confirm that the middle wafer is in fact a true Log Taper.

At 50% rotation, a 1K Log taper will measure 10% of total resistance, i.e. 100 Ohms.

with +/-20% tolerance, your part should measure between 80 Ohms and 120 Ohms.

is this the case?

Also (attached is a 'generic' taper graph.)

is it possible to post a similar graph using your new part?

I think I can do this,

We use this (http://groupdiy.com/gallery/0/57038-220116160438.gif)

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 22, 2016, 04:45:14 PM
Guys, Hello again everybody!
I pulled a few pieces out of the box, last order. Checked. All upside-down resistor 1K!!!!
I compared them with the first resistors that I currently use.
They are different!
Ian was right! Ian, please, sorry me! I am testing your and don't understand what he's telling me! My all from old order work well! All I sent you was from one of the box! I have not tested, could not even think about what might happen!
I am very sorry!
Don't worry! I will contact the factory and find out why it happened! Tomorrow all write!
I hope we can decide it in the coming days, I will send to all new resistors!

Thanks! Will inform you soon!

PS. Ian, please, sorry me!!! And thanks to you a lot!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ruffrecords on January 22, 2016, 05:41:40 PM
@AVDO

No problem. At least we know what went wrong.

Cheers

Ian
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 22, 2016, 05:53:20 PM
Ian, thanks!!!
I will check it at first, when I decide this!
I will send to you again how many do you need!

Please, sorry! I am very not pleased that I did!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ruffrecords on January 22, 2016, 05:57:32 PM
Ian, thanks!!!
I will check it at first, when I decide this!
I will send to you again how many do you need!

Please, sorry! I am very not pleased that I did!

Do not worry about it. Life is too short. I just tried to take one apart hoping I might be able to reverse the 1K part but the shaft is permanently fixed to the last 500R pot so this is not possible.

Just send me a couple of the correct ones.

Cheers

Ian
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 22, 2016, 06:05:03 PM
Ian,
I think it can damage this!
It will destroy the structure of the potentiometer that it can't work well.

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: Dreams on January 22, 2016, 06:07:05 PM
Side note:

If you could make these with a smaller shaft diameter, I'd buy a bunch of them.
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 22, 2016, 06:12:35 PM
Side note:

If you could make these with a smaller shaft diameter, I'd buy a bunch of them.

Which diameter do you need?


Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: andre tchmil on January 23, 2016, 02:42:51 PM
Just received an email from Avdo explaining what  went possibly wrong in the production.
I didn't tested or measured them myself . So I wasn't aware of this.

I just want to say  what a great and honest guy he is and he will solve the problem.
Be patient.

Dre
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on January 25, 2016, 07:26:07 AM
Hello guys!!!
Want to tell again to all!
I today speak with manufacture! We found a problem! Today we know why it happened.

I receive it again, with the new amendments, and they will produce it during two weeks. Hope I will have it in the middle of February.
I write all them I sent orders a samples!
At first, when I receive I will send all orders again by free shipping!

Please, guys, don't worry. Will inform you soon!

Thank for your understanding!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on February 03, 2016, 03:29:29 PM
Guys, hello!
Have a good news!
Today I receive new butch of T-Pad with corrected error! Today we have true log type.
As Ian told before, 1K resistor in half has around 830-860 ohm from different samples.
And has correct log line now!

Today and tomorrow I will prepare old orders, and I hope during two days I'll send it to all, who are waiting!

Will inform you here and by your mail!

If you have any questions please, ask me! If you want something, do the same! ;)

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: Dreams on February 03, 2016, 03:49:01 PM

Which diameter do you need?


1/8" shaft or close would be nice
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on February 03, 2016, 03:53:38 PM
Dreams,
will ask about this. Will inform you soon!

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on February 03, 2016, 05:11:53 PM
I connected 2-nd and 3-th wafer  like I do it in my line.
Photos with connected:
(http://groupdiy.com/gallery/0/thumb_57038-030216163825.jpeg) (http://groupdiy.com/gallery/0/57038-030216163825.jpeg)
(http://groupdiy.com/gallery/0/thumb_57038-030216163754.jpeg) (http://groupdiy.com/gallery/0/57038-030216163754.jpeg)
(http://groupdiy.com/gallery/0/thumb_57038-030216163720.jpeg) (http://groupdiy.com/gallery/0/57038-030216163720.jpeg)

Then, I make video - https://yadi.sk/i/LBo1xt5zoFnac
You can see how does it work. At first it down, then up.

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on February 05, 2016, 03:23:47 PM
Hello guys!
I sent today first part of new T-Pad, your track number I have sent you to your mail.
Who didn't receive it, please, wait, tomorrow I will send second part.

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on February 17, 2016, 08:00:33 AM
Dreams,
Sent you PM.

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ruffrecords on February 17, 2016, 01:01:50 PM
Mine arrived in the post yesterday. Many thanks for the Russian chocolate!!

I see the middle pot is now a reverse log type (C) so it should work. I will test and let you know.

Cheers

Ian
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on February 17, 2016, 04:24:44 PM
Ian,
thanks! Will wait your post!

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on February 17, 2016, 04:36:31 PM
Ian,
thanks! Will wait your post!

And chocolate will saturate you life)))

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: andre tchmil on February 17, 2016, 08:29:37 PM
received mine as well.
Russian chocolate was the first I've putted on my test bench.
The future looks bright !
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: ilfungo on February 23, 2016, 08:37:01 AM
Received!
Thanks Avdo!!!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on March 02, 2016, 03:09:34 PM
Thanks guys!
Have somebody tested new T-Pad? Any comments?

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: tardishead on March 26, 2016, 02:22:59 PM
What's the verdict
How good/bad are they??
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: andre tchmil on March 28, 2016, 07:09:04 PM
What's the verdict
How good/bad are they??

I like them,
work as they should.
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on March 29, 2016, 05:28:41 AM
Quote
I like them,
work as they should.

andre tchmil,
Big thanks for you reply!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on April 25, 2016, 10:28:53 AM
How I use it in my Pre!

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: kosi on April 26, 2016, 03:42:01 PM
Hi there,
I use it in my Classic Solo and it works perfect, very smooth feel.

good that I ordered 5 pieces :)
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: fonzobrown on May 02, 2016, 12:55:26 PM
Hi Avdo, payment done! I let You know as soon as i'll receive the parcel : )

Best wish

Rob
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on May 03, 2016, 09:09:24 AM
Thanks guys!
Have sent to all! Check please your mail!

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on June 02, 2016, 11:08:58 AM
Guys,

Have last 50ps in stock T-Pad!
If you need, please, welcome!!!

Thanks!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: andre tchmil on July 12, 2016, 08:14:12 PM
I could take a few more
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: skal1 on March 07, 2017, 02:51:37 PM
Hi avdo,

have still got any of these left..

regards

skal
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on March 07, 2017, 04:00:30 PM
Guys,
I hoped to received it in February. But manufacture has small delay.
I hope it will be soon in stock!
I remember about all guys who want it! But please, send me each of you mail to me. And I will inform you as I have it!
Or I will write it here and my WhiteMarket place!
Thanks to all, guys!
Title: Re: Cheaper T-PAD attenuator 600ohm from Avdo!
Post by: avdo on March 21, 2017, 05:36:10 AM
Guys, hello!

T-Pads arrived.

Will be able for order here: http://avdaudio.com/catalog.htm?pid=1370

Thanks!
Title: Re: FS: T-PAD attenuator 600ohm from Avdo!
Post by: craigmorris74 on September 13, 2017, 10:59:22 AM
I'm just now getting around to using these attenuators.  How are they supposed to be wired up?

Thanks,
Craig
Title: Re: FS: T-PAD attenuator 600ohm from Avdo!
Post by: TillM on September 13, 2017, 11:57:07 AM
same wiring like the t-pad from CAPI or Hairball.
Title: Re: FS: T-PAD attenuator 600ohm from Avdo!
Post by: craigmorris74 on September 13, 2017, 12:30:52 PM
same wiring like the t-pad from CAPI or Hairball.
OK, I think I've figured it out.  Thanks.