The Dude Posted June 18, 2015 Share Posted June 18, 2015 Why do I need gain in a preamp, is a passive right for me? I kind of sort of get the difference between passive and active preamps. Actives have or introduce gain, while passives don't. Well at least that is how I understand it, so my question to you guys is. Would a passive work for me? Right now I am using an active crossover with my Crown D45 on the hf horns, and my McIntosh MC2100 on the bass bins. Why am I thinking of switching to a passive you may? Well I have notice some issues with my tube preamp such as problems with the phono section, and cracks and pops all of sudden. I wanted to eliminate the preamp, by using something simple. Once I do that, I can take time to repair the tube preamp(or rob it for parts). I guess I could do this by just hooking up an ipod or something a like directly to the active crossover. Maybe I will give that a try once I get home this evening. I guess in a since I am looking for a low cost alternative to purchasing a preamp, once I diagnosis the problem. I only need 2 or 3 inputs, and once I pull my preamp apart I will turn it into a phono only preamp. Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted June 18, 2015 Share Posted June 18, 2015 Why do I need gain in a preamp, is a passive right for me? I kind of sort of get the difference between passive and active preamps. Actives have or introduce gain, while passives don't. Well at least that is how I understand it, so my question to you guys is. Would a passive work for me? Right now I am using an active crossover with my Crown D45 on the hf horns, and my McIntosh MC2100 on the bass bins. Why am I thinking of switching to a passive you may? Well I have notice some issues with my tube preamp such as problems with the phono section, and cracks and pops all of sudden. I wanted to eliminate the preamp, by using something simple. Once I do that, I can take time to repair the tube preamp(or rob it for parts). I guess I could do this by just hooking up an ipod or something a like directly to the active crossover. Maybe I will give that a try once I get home this evening. I guess in a since I am looking for a low cost alternative to purchasing a preamp, once I diagnosis the problem. I only need 2 or 3 inputs, and once I pull my preamp apart I will turn it into a phono only preamp. Get in touch with seti........ tc 1 Quote Link to comment Share on other sites More sharing options...
The Dude Posted June 18, 2015 Author Share Posted June 18, 2015 Get in touch with seti Does he have one for sale, or a design for a good one. But I will contact him. Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted June 18, 2015 Share Posted June 18, 2015 right around $200 after currency conversion.. http://www.tisburyaudio.co.uk/mini-passive-preamplifier Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted June 18, 2015 Share Posted June 18, 2015 You have gotten me confused. Are you going to be using a phono as a source? If it just a CD as a source, do you know the rms voltage it is putting out? Quote Link to comment Share on other sites More sharing options...
The Dude Posted June 18, 2015 Author Share Posted June 18, 2015 Are you going to be using a phono as a source? At times, but I have a phono preamp I could use. If it just a CD as a source, do you know the rms voltage it is putting out It would either be a CD as a source or computer. Quote Link to comment Share on other sites More sharing options...
The Dude Posted June 18, 2015 Author Share Posted June 18, 2015 right around $200 after currency conversion.. http://www.tisburyaudio.co.uk/mini-passive-preamplifier Actually I was thinking I would rob the volume knob and selector switch out of my pre amp and build one. . Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted June 18, 2015 Share Posted June 18, 2015 Both amps have a reasonable input sensitivity so, with a CD player as a source, a passive attenuator should be ok assuming you don't play music so loudly that you have to max out the power. I've posted the schematic below before, but here it is again. You can build two mono units, or a stereo unit. Use a rotary switch or a couple of toggle switches to handle the multiple inputs you need, and keep the interconnects on the output side as short as is feasible. Maynard simple-passive-attenuator.pdf Quote Link to comment Share on other sites More sharing options...
djk Posted June 18, 2015 Share Posted June 18, 2015 http://schiit.com/products/sys Two inputs. 1 Quote Link to comment Share on other sites More sharing options...
The Dude Posted June 18, 2015 Author Share Posted June 18, 2015 If I was to only use my computer that has a volume control, could I get away without having to use anything and just hook directly up to the active crossover Quote Link to comment Share on other sites More sharing options...
The Dude Posted June 18, 2015 Author Share Posted June 18, 2015 http://schiit.com/products/sys Two inputs. This is what sparked my interest. Quote Link to comment Share on other sites More sharing options...
No.4 Posted June 18, 2015 Share Posted June 18, 2015 http://khozmo.com/products_dale_shunt.html These are very nice, many options depending on how diy savvy you want to be. A little pricey but you will never need another attenuator. I could not be happier with mine. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted June 19, 2015 Share Posted June 19, 2015 If I was to only use my computer that has a volume control, could I get away without having to use anything and just hook directly up to the active crossover Yes, assuming the voltage output of your sound card is adequate. It can't hurt to give it a try. Maynard 1 Quote Link to comment Share on other sites More sharing options...
The Dude Posted June 19, 2015 Author Share Posted June 19, 2015 If I was to only use my computer that has a volume control, could I get away without having to use anything and just hook directly up to the active crossoverYes, assuming the voltage output of your sound card is adequate. It can't hurt to give it a try.Maynard Yes it seems to work fine. Tonight I will be playing with the system and see what happens. If the weird pops go away I will know it is in the pre amp. For now I am only playing music from my computer. When I go to add another source I will need to do something for source selection. Quote Link to comment Share on other sites More sharing options...
NBPK402 Posted June 19, 2015 Share Posted June 19, 2015 If I was to only use my computer that has a volume control, could I get away without having to use anything and just hook directly up to the active crossoverYes, assuming the voltage output of your sound card is adequate. It can't hurt to give it a try.Maynard Yes it seems to work fine. Tonight I will be playing with the system and see what happens. If the weird pops go away I will know it is in the pre amp. For now I am only playing music from my computer. When I go to add another source I will need to do something for source selection. Oppo 103 or 105 player... They have dual HDMI inputs. You can then run from the Oppo via analog out to a passive preamp. Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted June 19, 2015 Share Posted June 19, 2015 Just be aware that all passives are NOT created equal. Resistor based passives are ones to avoid. Transformer, Autoformer, or LDR is where you want to go. If you have sufficient input sensitivity with your amp and enough voltage output with your source, a good passive device is hard to touch. Shakey Quote Link to comment Share on other sites More sharing options...
djk Posted June 19, 2015 Share Posted June 19, 2015 "Resistor based passives are ones to avoid." So a light dependent resistor is bad too? Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted June 19, 2015 Share Posted June 19, 2015 "Resistor based passives are ones to avoid." So a light dependent resistor is bad too? No, I was referring to conventional resistor preamps. An LDR is a different animal indeed. Shakey Quote Link to comment Share on other sites More sharing options...
No.4 Posted June 20, 2015 Share Posted June 20, 2015 "Resistor based passives are ones to avoid." So a light dependent resistor is bad too? No, I was referring to conventional resistor preamps. An LDR is a different animal indeed.Shakey Why? Quote Link to comment Share on other sites More sharing options...
Shakeydeal Posted June 20, 2015 Share Posted June 20, 2015 Well I have owned both and it's not even close. With an LDR there are no pots, relays or switches in the signal path. Shakey Quote Link to comment Share on other sites More sharing options...
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