I am putting my preference for sound quality before convenience, this is, as I have already pointed out, my preferred pre with my CURRENT power amp. I leave my options open and will try both with the new power amp when I get it finished. One advantage I have noticed when using the active pre (so far) is enhanced bass performance, especially late at night when the volume is low. I still get decent bass and it reduces the slight sharpness I hear in the high frequency's. Everything in life has compromises involved somewhere.
Hi Davy
I believe that the original JC 2 used a 10K pot with a switchable 10K resistor on top of it to adjust the gain.
That may allow you enough flexibility for your different sources.
I have a 10K ebay switcher on my JC 2 and had plenty of adjustment volume wise so I’d do like you say and build the amp first.
That way you can be sure,
of what is going to work best for you.
I believe that the original JC 2 used a 10K pot with a switchable 10K resistor on top of it to adjust the gain.
That may allow you enough flexibility for your different sources.
I have a 10K ebay switcher on my JC 2 and had plenty of adjustment volume wise so I’d do like you say and build the amp first.
That way you can be sure,
of what is going to work best for you.
I tried removing the JC-2 earlier tonight and just used my passive pre, not nearly as good, less dynamic sound and where has all that lovely bass weight gone
Your chipamp would probably need a pre then.
With the My_Ref it will be different.
"When you come to a fork in the road - take it"
My experience convinces me that preamps are much like capacitor choices. During a long afternoon of listening I sometimes feel various tracks/styles would sound more "realistic" with one of the other input caps. I think that holds true for preamps also. Generally, I lean toward the JC-2 with jazz and pop due to the bump in warmth, color and dynamics. That doesn't always fit with some more complex classical pieces. My personal preference is the Lighter Note (or other LDR unit) for those. I don't think I'll ever choose to eliminate one or the other - but most likely will build a switch of some sort to go between both without having to mess with the interconnects.
Over the past week I have been concentrating on listening to the SACD material I have. My impressions are similar. That trite old saw "The speakers seem to disappear" is the most obvious advantage I'm perceiving. the stage is more stable and accurate, more space and definition of voices/instruments.
However, there are a few tracks on mp3 and/or flac that present a bit of "in your face" quality that I really like. I'm learning that a lot of that could be from distortion elements. Nelson Pass talks a lot about compromises between second and third order harmonics in amp design. He incorporates pots and trimmers to dial in a users sweet spot, knowing the universal optimum is realistically not going to happen. My guess is that a "best" preamp for the FE will also prove to be a preference and not an absolute.
So I say keep a couple pres in your stash. You know every time I have to go out for amp parts I have to decide whether to drive the Rolls, the Bugatti, the Mustang or the Harley - why should I limit my preamp choices?
P.S - Lance Armstrong gave me one of his old bikes also - but I'm too old and keep falling off.
My experience convinces me that preamps are much like capacitor choices. During a long afternoon of listening I sometimes feel various tracks/styles would sound more "realistic" with one of the other input caps. I think that holds true for preamps also. Generally, I lean toward the JC-2 with jazz and pop due to the bump in warmth, color and dynamics. That doesn't always fit with some more complex classical pieces. My personal preference is the Lighter Note (or other LDR unit) for those. I don't think I'll ever choose to eliminate one or the other - but most likely will build a switch of some sort to go between both without having to mess with the interconnects.
Over the past week I have been concentrating on listening to the SACD material I have. My impressions are similar. That trite old saw "The speakers seem to disappear" is the most obvious advantage I'm perceiving. the stage is more stable and accurate, more space and definition of voices/instruments.
However, there are a few tracks on mp3 and/or flac that present a bit of "in your face" quality that I really like. I'm learning that a lot of that could be from distortion elements. Nelson Pass talks a lot about compromises between second and third order harmonics in amp design. He incorporates pots and trimmers to dial in a users sweet spot, knowing the universal optimum is realistically not going to happen. My guess is that a "best" preamp for the FE will also prove to be a preference and not an absolute.
So I say keep a couple pres in your stash. You know every time I have to go out for amp parts I have to decide whether to drive the Rolls, the Bugatti, the Mustang or the Harley - why should I limit my preamp choices?
P.S - Lance Armstrong gave me one of his old bikes also - but I'm too old and keep falling off.
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By the way - I did find a gem last week. It's a James Taylor track that is super clean, has "in the room" guitar work, background vocals and a pristine triangle that really shimmers. It's a flac translation of a SACD master that comes in at 121 Mb - but well worth the download time -IMHO. Could easily become a FE test standard.
My Traveling Star
My Traveling Star
I like to use both well recorded material which in general sounds good on any system and some not so well recorded material (spoilt for choice there) to give me an overall impression of my system, such as it is. I've just been trying out a few options and the best I've found so far is my passive pre with it's input selector and 20k stepped pot feeding my JC-2 with a 10k stepped pot fitted to it. I found that if I leave the PC's own volume at max, and leave the JC-2's pot set at roughly 2/3 volume, I can then use the passive pre to select the source and control the volume with a decent range of movement and good sound quality. This arrangement gave me the best results (so far). Things may well change again when I get the FE finished
If you are going in that direction, let me suggest a setup.
1. If you are on a PC make sure all the formats are enabled in the sound section of the control panel.
2. If you use JRiver you can select WASAPI to completely eliminate the Windows audio drivers. That cleans things up a bit and your JC-2 pot gets a full-strength straight-through feed.
The same is probably doable on a Mac but I'm not that familiar with Mr. Jobs approach - and the available players
1. If you are on a PC make sure all the formats are enabled in the sound section of the control panel.
2. If you use JRiver you can select WASAPI to completely eliminate the Windows audio drivers. That cleans things up a bit and your JC-2 pot gets a full-strength straight-through feed.
The same is probably doable on a Mac but I'm not that familiar with Mr. Jobs approach - and the available players
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Hi Bob, I tried WASAPI some time last year but I am using a PC/ Musical Fidelity V-Link/V-DAC set up for digital which does not work with WASAPI. It does give the best digital sound quality I've had to date though, it usually makes my turntable sound poor in comparison but I have to leave the PC volume at max for best results. I sold my Rega Apollo CDP after getting this set up working. I still have an old Philips CDR, somewhere in the house, probably the loft. Having boxes of CD's all over the place hacked me off and I had trouble finding CD's I wanted to hear.
Musical Fidelity VLink II USB to S/PDIF Converter
The technoblurb has the same effect that most digital spiel has on me, I feel my eyes growing heavy and concentration wan....
....
Anyway it seems to work well enough
Musical Fidelity VLink II USB to S/PDIF Converter
The technoblurb has the same effect that most digital spiel has on me, I feel my eyes growing heavy and concentration wan....
....Anyway it seems to work well enough
That was my impression, the JC-2 clone has x3 gain but a stepped attenuator fitted to it and left set at roughly 2/3 volume seems to have given me the best solution. It is, effectively, just a buffer now.
times 3 gain is canceled by times 1/3 attenuation, so that the input signal is at the same level as the output signal.
Applying most source levels to most amplifier sensitivities will take the amplifier output to near clipping. It could be over the clipping level, or it could be under the clipping level.
I never run my amps close to clipping. I hear you re the pot position, when I try leaving the pot on the active pre set at or below half volume it sounds dull and lifeless, once I get a bit past the mid point, the sound comes alive, at much over 2/3 volume I am back to having not enough adjustment on the passive pre and it goes way to loud too fast. It seems that roughly x2 gain on the active pre/buffer gives me the best sounding results so far. The new amp will probably not need a buffer at all but I will try it with passive, active and both together to see which combination gives the best results in my setup.
You have got the wrong impression, i probably confused the issue as usual. I have a small diy passive pre which has an Elma rotary switch for source selection and a 20k stepped attenuator. I have my sources plugged into this. At present this is feeding my active pre which has a 10k stepped attenuator fitted through the back panel beside the RCA sockets. I leave this set at a fixed position to reduce the gain, it means I can still adjust it if needed. The active pre/buffer then feeds the power amp.
I use the passive pre for normal volume adjustment and source selection. I have been trying various settings for the 10k pot on the active pre over the past couple of days, I got the impression that if I left it pre-set at mid way or less, I was losing a certain amount of impact but after a bit more testing, I now believe this was a false impression. As of last night, the (fixed) position for the 10k pot is at just under 1/3 of its available travel. So the passive pre is now used for all adjustments and the active unit it feeds into is just being used as a buffer with no gain. I now get a reasonable range of volume adjustment on the passive pre and have the increased bass weight at low listening levels which I get from the active buffer. A compromise as usual but it gives me decent results. Before I had to reduce the PC's inbuilt volume setting which had a worse effect on the sound than my current arrangement but that did not help with my phono stages output which remained too high for reasonable volume adjustment on the passive pre.
Maybe I can go back to just using the passive pre on it's own with my new power amp, when I get it built.
I use the passive pre for normal volume adjustment and source selection. I have been trying various settings for the 10k pot on the active pre over the past couple of days, I got the impression that if I left it pre-set at mid way or less, I was losing a certain amount of impact but after a bit more testing, I now believe this was a false impression. As of last night, the (fixed) position for the 10k pot is at just under 1/3 of its available travel. So the passive pre is now used for all adjustments and the active unit it feeds into is just being used as a buffer with no gain. I now get a reasonable range of volume adjustment on the passive pre and have the increased bass weight at low listening levels which I get from the active buffer. A compromise as usual but it gives me decent results. Before I had to reduce the PC's inbuilt volume setting which had a worse effect on the sound than my current arrangement but that did not help with my phono stages output which remained too high for reasonable volume adjustment on the passive pre.
Maybe I can go back to just using the passive pre on it's own with my new power amp, when I get it built.
There is no point in adding excess amplification and then canceling that un-needed gain by using more attenuation.
Have you read?
What is Gain Structure? - diyAudio
Have you read?
What is Gain Structure? - diyAudio
I would normally be among the first to agree. I'll have a read through your linked article later on when I have more time but I am going by what sounds better to me. Without the added buffer my old vinyl is practically unlistenable, really bright sounding with almost no bass to speak of. The buffer makes a better job of the vinyl without making the digital source sound bad. At the end of the day, I have to be able to listen to the system and I have not been playing many lp's of late because of the sound quality. I have been able to enjoy my old lp's again since I set this up. Horses for courses springs to mind.