I want a preamp that sounds like this...
- Thread starter lJelal
- Start date
AmadeusMozart
Well-Known Member
He wants to have a musquito repellant. ;-)
But all seriously there is no tweeter going that high. Kef wanted to build scale models of concerthalls (of which the LS3/5A was an offspring) and they had to create a special transducer to go from about 40Khz upwards.
I remember that there was at one stage an article that stated that an amplifier had to go to 100Khz although IIRC that was to ensure that global negative feedback was implementd properly and no oscillation was present. There was a lot of furore about that article as the 100Khz was regarded as being over the top.
There have been tests with high end (solid state) headphone amplifiers that showed that music replayed with a cutoff of 20Khz sounded "harsh, analytical". Another test showed that music was expereinced as "warm, enjoyable" when the cutoff was.... 16 Khz! This also was the case with an older, highly sought after (at least in Japan) Sansui amplifier (HK-V60 - Audio Note designed a clone based on that design: Audio note kit 4 ). I build the Audio note kit 4 after reading reports it was highly regarded. Square wave had totally disappeared by 10 Khz.
I've now got a tube amplifier with the square wave perfect up to at least 50 Khz (where my test equipment starts showing its defects) and the amplifier response is (at least) better than -1dB at 90Khz (measured with a HP339A). The amp is very revealing but some music is next to unlistenable due to notice every defect in recordings or source: e.g. a PC as source is no longer acceptable, same as many radio stations are sounding horrible.
Voice reproduction has become very intelligible and enjoyable but the clearer performance is a two-edged sword.
Perhaps the OP should instead of looking at spending mega dollars first try using an EQ with a cut off stuff above 16 Khz and see how he likes that.
If the OP wants eventually to buy something I suggest he tries a QUAD QC 24 preamp out first - it might only go to 50kHz @ -0.5dB but Quad is known for a warm sound. https://www.quad-hifi.co.uk/qc-twenty-four/
AM
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lJelal
Member
I really appreciate the genuine suggestions made so far. It's odd to me that a few people add to this thread making incorrect assumptions about what I have or have not done.
In the first post, I have included a sample of the sound I like with substantial frequency extension & described the attributes of this sample in the ways I perceive them. Here it is again. https://gofile.io/d/Hw6Cmw
My hope is that someone would take the time to listen and then suggest a preamp that has those characteristics. That would be extremely helpful.
In the first post, I have included a sample of the sound I like with substantial frequency extension & described the attributes of this sample in the ways I perceive them. Here it is again. https://gofile.io/d/Hw6Cmw
My hope is that someone would take the time to listen and then suggest a preamp that has those characteristics. That would be extremely helpful.
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FlaCharlie
Super Member
Well, I listened.
But, frankly, the notion that someone could make a valid suggestion based on that is totally flawed. That's because everyone listens to the sound sample through their own system, and each and every one of them is different.
And we all listen to systems, which include different amps, speakers, rooms etc. While we can try different components in our systems and hear differences, it's very difficult to determine how much a particular component (in this case a preamp) will affect the overall presentation of someone else's system.
Perhaps this is especially true in the case of preamps.
How many times have you heard people say the best preamps are totally transparent and add nothing to the "sound". Not saying I agree with that. The preamp I built, the Boogie Factor 1626, does add something and I like the result.
https://www.audiokarma.org/forums/index.php?threads/1626-preamp-build.931276/
I have no idea how it measures and, frankly, I don't care. I also have a Yamaha C-85 and I'd say that it comes close to not having a "sound". My experience with preamps is limited, though, so perhaps it sounds warm compared to some others.
But I suspect that many people would say that, compared to other elements in the system, that the preamp often has less influence.
Based on the description in your initial post, I'd suggest you try something that uses DHTs, directly heated triodes. I'm into DIY but I'm sure there are commercial products that use these types of tubes.
For my most recent amp build I ended up using 26s on the input but during the breadboard process I tried numerous other DHTs and triode strapped DH pentodes.
https://www.audiokarma.org/forums/index.php?threads/the-nuance-my-inverted-set-diy-project.990205/
Most all of them sounded nice but the 26 had a combination of warmth and detail that I found very appealing. To my surprise, I also found that there was quite a variation between the ST shape 26s and the older globe style version. The STs were warmer, bordering on lush, while the globes were more detailed and can be downright spooky when it comes to sound stage.
But, again, that's in my system and YMMV, as always. And my implementation of the both the 1626 and the 26 is in a super simple circuit. In a more complicated circuit they might sound somewhat different.
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lJelal
Member
My hope is that someone already knows the Dynaco PAS 3 sound. They recognize that sound (which is in the sample) and they know other gear that has similar sound but better frequency extension and lower noise. I know that this a highly imperfect exercise, but I don't think it is impossible nor improbable. The suggestion of the Atmosphere UV-1 is my evidence.
AmadeusMozart
Well-Known Member
^^^
Truth, all the YouTube videos and downloaded music sound the same on my laptop speakers.
You don't seem to assimilate what @FlaCharlie said: one cannot "recognize" the sound of your system on their system.
I'm done.
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santa
Well-Known Member
I would imagine that most preamps that are flat to 100 KHZ employ copious amounts of negative feedback to achieve those specs and that seems like it would be counterproductive to one seeking a less analytical presentation of the program material.
I would recommend having a listen to Pass Labs preamps as they do sound wonderful but won’t have the bandwidth you desire.
I would recommend having a listen to Pass Labs preamps as they do sound wonderful but won’t have the bandwidth you desire.
Listen to @GordonW. He knows his stuff. Works with and handles stuff in the many thousands of dollars range. He is my go to on any problems I have with my equipment.OK - thank you Guys !
Originally, I would have been pleased to find a SP3/SP3A, but the SP6B seems to be a good compromise, right ?
Cheers,
T
FlaCharlie
Super Member
Correct me if I'm wrong, but I don't think anyone who listened to your sound clip in this thread suggested the Atmosphere UV-1. So I'm not sure how this validates your approach of asking people to make recommendations based on a sound sample.
Earlier you posted: "Another one for the list is the Atma Sphere UV-1. It is a refinement of the Dynaco PAS 3 circuit. I spoke to Ralph about the SNR. He said it's in the 90s."
I looked up the UV-1 and Ralph is the designer. Did he listen to your sound sample in an online post, respond, and suggest that his preamp ($1900 line stage only, up to $2800 including a phono pre) would provide what you're looking for?
Or did you contact him, after reading that the UV-1 is based on the PAS, and simply ask him about the SNR? The unit's SNR is not one of the specs he publishes, BTW.
The line stage section of the UV-1 seems pretty standard, according to a description of the circuit in a review. It uses a pair of 6SN7s with one section as a gain stage and the other configured as a cathode follower. The cathode follower gives it a low output impedance that's suitable for use with a SS or Class D amp. It certainly looks to be well made but I suspect commercially sold preamps that use the same circuit could be found for much less $$$. It could be built for a few hundred dollars or less.
I'm not real familiar with the PAS. Although I do own one, it's been on the shelf for many years. As I recall it uses 12AX7s, whose amplification factor is 5x higher than the 6SN7, and I don't think it has a cathode follower stage. So it seems as though the line stage sections of the PAS 3 and the UV-1 are totally different.
Bottom line . . . if your sound sample was recorded using the line stage section of a PAS 3, I would not expect the line stage of the UV-1 to sound the same.
Looking around a bit further, it seems like it's the phono section of the UV-1 that somewhat resembles the PAS. Although he doesn't release schematics, I found a post where he describes the differences, the most obvious of which is that he uses 12AT7s instead of 12AX7s.
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This is one very curious thread.
lJelal
Member
This is not the sole venue in which I have posed these questions. The claim that the Atmosphere UV-1 was based on the PAS 3 seemed to make it a strong candidate for my list. I did reach out to confirm the SNR numbers since they are not documented. The numbers for the phono stage look good @ 5 Hz-90 KHz within .5 dB so if that gives it a similar voice, I am still interested. I certainly expect build differences given the higher specifications and noise reduction compared to the PAS 3. If there is a better recommendation for something to consider - I am all ears.
FlaCharlie
Super Member
Well if you use a turntable, then the phono section of the UV-1 would be considered a modded (and presumably upgraded) PAS. But the line stage section is nothing like the PAS. If someone told you otherwise, you've been misled.
Was the sound clip you made as your reference recorded with the line stage or phono stage of the PAS?
If your main interest is the phono stage it would be easy enough to mod a PAS to match the circuitry. The differences are described by the designer in a post on Audiogon. If you use military spec metal film resistors and add some filtering to the power supply there's no reason why you couldn't get the same level of performance for a parts cost of maybe $100 or less. Or feel free to pay $2300 for the same circuit in a fancy box.
Given that the PAS has been the basis for many mods over the years, it's entirely possible that some of them may sound even better than the UV-1 version. There seem to be numerous aftermarket boards for all the Dynaco gear.
I'm not into vinyl, but the phono stage I keep hearing about lately is the EAR, which apparently comes in both kit and finished form.
You might find some of @StepheK 's YT videos to be helpful. She built and reviewed an EAR phono stage and also did a preamp (line stage) shootout. The preamp that won her shootout uses 6SN7s and I don't think it's a kit. Someone sent it to her to test. She says it has a much warmer sound than the others.
Her videos are excellent. https://www.youtube.com/c/SkunkieDesignsElectronics/videos
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AudioAvarice
Super Member
I still think it would be worth your while getting an X-10D buffer for your C85, they are peanuts compaired to what you considering, and easy to resell if it's not for you. They were designed as a 'replacement' output stage for low-mid level 90's CD players after all, and did it very well. Admittedly when used with quality components the effect is more subtle, but still very enjoyable.
I used modified and stock PAS preamps on and off for about thirty years. That’s until I bought the Chinese EAR clone phono stage and immediately enjoyed it much more. Dynamics, soundstage, much lower noise level……… The Marantz 7 clone blows away every PAS I have experienced, although none were heavily modified. Different strokes, maybe but I don’t see the point in modifying the old PAS. Pretty nice preamp but it is what it is. Some may strongly disagree with my opinion. Fine.
Those "black PC board" EAR 834 clone phono stages sound REALLY good. I've been building them from ebay kits, checking every component, replacing any that are out of spec, using high quality pf caps for the equalization circuit and mundorf alum oil caps for coupling, and everyone I have taken over for someone to audition in their high end systems have bought one. Drop in 3 EH7025 tubes (or NOS RCA if you wanna spend a little more) and they sound fantastic.
Dynaco PAS3 Series II or the PAS4 is very good sounding tube preamp that is worth checking out and they works well with both SS amp and Tube amps. The older PAS3 / PAS3X may be a bit too system dependent.
I have tried both PAS3 Series II and PAS3X in the past so speaking from my own experience.
I have tried both PAS3 Series II and PAS3X in the past so speaking from my own experience.