So why do you say:
unless, if I got it properly, AOK is better than OK, right? 😉
Elso Kwak said:
unless, if I got it properly, AOK is better than OK, right? 😉
I jus' hunt down the right old Pioneer and Panasonic stereo units (preferrably broken!) and scoop their Stepped plastic film attenuators....take apart and clean if needed...and then configure as a shunt volume..with the appropriate resistor..and hey! presto! we be rockin! I'm done....
panasonic's top recievers from 1977 had the right volume pot for this trick.
panasonic's top recievers from 1977 had the right volume pot for this trick.
I got some nice alps pots from 1970s Blaupunkt tape deks too, a shame they are 100k, will get a use for them some day though.
Guys, could you give me your opinion of what you think about the Dale Vishay Stepped Attenuator 100K in the link below, for use in a tubed pre.
I would appreciate some opinions or suggestions how to best use this b4 I buy one. Thanks.
Dale Vishay Stepped Attenuator
I would appreciate some opinions or suggestions how to best use this b4 I buy one. Thanks.
Dale Vishay Stepped Attenuator
Nuuk, thank you for your contribution. I am going to get a 100K impedance unit to replace the damaged Alps in my tube preamp. Would appreciate any further tips on implementing this stepped attenuator. Nuuk, you mentioned specificaly concerning values. Could you please elaborate as I am not good at these things. You think it would be alright if I did what I wrote above about just swapping the Alps out with the same value? Thanks.
BTW, I have also purchased some 10K and 50K Taiwan alpha log pots from Jaycar. Could someone who have used these pots please enligten me on which is the input pin, the output pin and the ground. Or is it standard that if you look at it from the front, the left is input, the middle is output and the right is ground?
BTW, I have also purchased some 10K and 50K Taiwan alpha log pots from Jaycar. Could someone who have used these pots please enligten me on which is the input pin, the output pin and the ground. Or is it standard that if you look at it from the front, the left is input, the middle is output and the right is ground?
I'm no expert on valve stuff so it may be a good idea to check on the valve forum. But if you are replacing a 100K pot then it should be absolutely fine.
My comment was more to do with getting the correct impedance when using the attenuator with NOS DACs, inverted GC's or class-T amps. 😉
Nuuk, thanks alot again for a very speedy reply. At the moment my system runs from a CD player into the tube pre and then finally into Peter daniel's LM4780 parallel GC. At some stage, I hope to build and try out Peter's NOS DAC too. Do you think it may then be a problem and how should I go about matching the impedance?
Another issue that came to my attention is that presently, the connection between the input RCA and the Alps pot is with a 100k resistor. Some of my friends had said that this is not right, and there should be another resistor between input and ground on the pot. I think they refered to this as L-Pad. What's your thoughts and how do you calculate the values?
Thanks again.
Another issue that came to my attention is that presently, the connection between the input RCA and the Alps pot is with a 100k resistor. Some of my friends had said that this is not right, and there should be another resistor between input and ground on the pot. I think they refered to this as L-Pad. What's your thoughts and how do you calculate the values?
Thanks again.
I can't think of any reason to just have a 100K in series with the volume control as it would change the attenuation! As your friends suggest, another resistor to ground forming an L-pad would be more logicall but quite why you would have two voltage dividers next to each other I am not sure! What valve pre are you referring to?
If you have an active pre (or buffer) between the NOS DAC and the amp, there should be no problem but if the NOS DAC output goes directly to the volume control, that should have an impedance of at least 20K if it's anything like the Scott Nixon DacKit or Monica2 NOS DAC.
Another option (perhaps instead of the pre) is the HDAM buffer sold by Burson Audio. I have a review of that coming out on TNT so don't want to give away too much here but do read the review! 😉
If you have an active pre (or buffer) between the NOS DAC and the amp, there should be no problem but if the NOS DAC output goes directly to the volume control, that should have an impedance of at least 20K if it's anything like the Scott Nixon DacKit or Monica2 NOS DAC.
Another option (perhaps instead of the pre) is the HDAM buffer sold by Burson Audio. I have a review of that coming out on TNT so don't want to give away too much here but do read the review! 😉
Nuuk, I think the resistor in series with the pot was to attenuate the signal b4 it goes into the Alps pot. My pre is a DIY clone Matisse Fantasy MkII.
What I'll do is I'll check with the friend who built my pre and ask him for the reasoning behind it.
Thabks again. I have just ordered the Vishay / Dale stepped attenuator and I am dying to get my hands on trying it out to see if I hear any difference. BTW, how do you burn in the resistors all at one go since it's a 23 stepped attentuator? Any simple suggestions short f running it at each position for 40 hours?
What I'll do is I'll check with the friend who built my pre and ask him for the reasoning behind it.
Thabks again. I have just ordered the Vishay / Dale stepped attenuator and I am dying to get my hands on trying it out to see if I hear any difference. BTW, how do you burn in the resistors all at one go since it's a 23 stepped attentuator? Any simple suggestions short f running it at each position for 40 hours?
I suspect tha tit was used in a system where the power amp had a lot of gain and it didn't leave much room for adjustment of the volume! Using an L-Pad type attenuator is quite common. You can even buy them fitted inside a phono plug!
It's much better to adjust the gain of the whole system so that you don't need that extra attenuator. With DIY, that's reasonably easy!
Don't worry about burning in the attenuator. It will probably sound a little 'strange' to your ears for the first day or so. But you should recognise an improvement over the pot and you will soon forget about burning in all those resistors. 😉
Nuuk, thanks again for your informative reply. I think you hit the nail on the head too. It's the pre that has very high gain. Any suggestions outside of the L-pad?
I'll be counting the days till the stepped attenuator arrives. BTW, this evening I heard a DIY MFA pre and a DIy tube amp. Source is a Linn Sondek LP-12, forgot the make of the speakers. Man, it's one of the better systems that I heard. Come to think of it, the systems that I have auditioned and liked are all DIY. 😀
I'll be counting the days till the stepped attenuator arrives. BTW, this evening I heard a DIY MFA pre and a DIy tube amp. Source is a Linn Sondek LP-12, forgot the make of the speakers. Man, it's one of the better systems that I heard. Come to think of it, the systems that I have auditioned and liked are all DIY. 😀
Nuuk, my Vishay stepped attenuator arrived from HiFi Collective yesterday and I had it in the preamp immediately. It's a nice looking equipment. Thanks for the advice. I have a problem though. When I turn the knob, each time it changes step, a 'pliak' comes from my speakers and it gets louder as the volume is increased. 😕 Do you have this problem and if you any suggestions?
Thanks again.
Thanks again.
It sounds like you have some DC adjacent to the attenuator. If you can show us what you are using it with, we should be able to help although it may entail a DC blocking cap! 😉
Nuuk, I gotta be on the road for a week from tomorrow but after I am back, I'll post some pics and maybe you'll be able to help me. Thanks.
I dropped it in to replace an ALPS 'Black Beauty' and my system virtually changed so much. The stage opened up and my walls seem to have disappeared, the details were extra good, bass was powerful and tight and some harshness that I use to experience has virtually disappeared.
Don't think I can go back to a volume pot after this. 😀
I dropped it in to replace an ALPS 'Black Beauty' and my system virtually changed so much. The stage opened up and my walls seem to have disappeared, the details were extra good, bass was powerful and tight and some harshness that I use to experience has virtually disappeared.
Don't think I can go back to a volume pot after this. 😀
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