jazzmessengers
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Posts posted by jazzmessengers
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2 hours ago, wdecho said:
I would love to own one of the SIT amplifiers. A lot can depend on the SET 300B and the tubes used about being better. Certainly the 300B is more linear if one looks at a chart but for SS buffs the SIT's are as close as one can get to a SE 300B. The curves are similar but the 300B beats a SIT transistor. I say grab one if you can find one for sale. There is supposedly a diy SE in the works using some of the V-fets in a circuit designed by Nelson. I have been waiting for it for many months. It may come out as a kit but I can get by with just a board and schematic hoarding some of those precious V-fet transistors years ago.
For single ended Michael R (won't attempt to spell his last name!) has some designs with the Sony VFETs. If you replace the light bulb version with large power resistors that is similar to the SIT-1 schematic. My theory is it is the output transformer that is the limiting factor. The 300B is indeed incredibly linear but then it is has this huge air gapped output transformer coming after it. The amp was running WE 300B, driver was JJ ECC99, interstage transformers were Tango NC20. These days for a "no-compromise" SET or DHT P-P (ala Lynn Olson Karna) I would probably go for transformers from Monolith Magnetics.
I am keeping my eyes open for a used SIT-1, unfortunately I don't have as much free time to spend online and these are usually bought up quickly. I may ask Reno hifi to let me know the next time he gets a demo unit.
Years ago before I got into DIY I experienced the incredible customer service of Pass Labs with the old Aleph 3.
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1 hour ago, jwc said:
Dont think he didnt recommend. He was just answering my question.
It's in his first post.
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1 hour ago, wdecho said:
One is not going to beat the deal for an adequate heatsink chassis' at diyaudio.com. I use this one myself but one must drill and tap the holes. https://diyaudiostore.com/collections/chassis/products/dissipante-4u For a ready to use, holes already drilled with back panel already cut and drilled go with this one in steel.
https://diyaudiostore.com/collections/chassis/products/deluxe-4u-amplifier-chassis-steel Aluminum one is a few dollars more. https://diyaudiostore.com/collections/deluxe/products/deluxe-ultimate-amplifier-chassis
The price includes shipping which one is not going to get from Asia. I have searched for better deal many times without beating these deals. Before they were made available I use to buy the heatsinks and build my own case from https://www.heatsinkusa.com/ Not a easy task I would want to do anymore with the cheap prices diyaudio store has now.
Yeah I know these are high quality cases. They are actually from Hifi2000 in Italy, and I've bought direct from them before the DIY Audio store existed. After that experience I would much rather order from someone in the US.
I was going to go with the 5U deluxe since the 10 mm front panels are incredibly nice. I have them on my 2U case that I use for a headphone amp.
I was actually in touch with someone from Thailand that sells FirstWatt clone cases but they are pretty expensive and I don't know what the dissipation rating on the headsinks is. I personally like the look of these more and I was eventually going to buy Pass' commercial SIT-1 amps to use on the midrange/treble horns. I heard those amps back to back with a high end custom built 300B SET amp using nickel output transformers and all of us thought the SIT-1 was more transparent and much better on complex symphony music.
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@justinsweber why wouldn't you recommend the DIYAudio store chasis? I was considering one for a build because with their PCBs it would be pre-drilled. I don't have the tools to do that myself and places like FrontPanelExpress charge a decent amount for that.
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The VFET FirstWatt amp that was sold as kits via DIY Audio is another incredible sounding amp.
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On 3/2/2018 at 12:52 AM, muel said:
Rather off the OP's topic but I tried 4 of their (Universal Music Japan) SHM-CD's and was pretty UNimpressed with their dynamic range... actually on the lower end of the spectrum compared to other versions on the DR database. Now what I bought weren't exactly typical audiophile albums but some rock CD's that I either didn't have and were on my "buy some day" list or I wanted a better version. Expensive fail for me. You might say I don't have a "yen" for anymore.
The "SHM" is just some marketing thing that was invented by the Japanese. You specifically want the Platinum series, otherwise the number of regular SHM releases are probably over 1000 and the mastering on these type of discs is more often compressed with the treble boosted. These are just regular reissues with the "super high material" designation applied to them.
The very short lived Platinum series were genuinely flat transfers from either US or UK master tapes and verified by the engineers that people have contacted them about (it is also written in the booklets). These were basically created as archives of master tapes (some other labels are digitizing their analog master tapes like Blue Note and Decca) that the Japanese released on CD and SACD.
Sorry didn't see this or your message earlier, my practice has been incredibly busy this year and I haven't had much time for message boards.
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On 1/28/2018 at 9:53 AM, Chris A said:
You might want to look at the tracks themselves to see if what you've read is actually true. From my demastering experiences from my own CD music library, I've learned that you will likely be surprised.
A link to that thread would be nice for others to follow from this thread. I might pick the wrong thread.
Note that I was referring to the ubiquitous two-to-five channel sound processing in my reference above--that creates a delayed sound field from the stereo original to create delayed surround channels in a 5.1, 7.1, etc.
I've found that loudspeakers that cannot control their polar coverage vs. frequency don't have many virtues--no matter how much some wish to think better of them. There are other issues (notably loss of clarity--among others) that are introduced when the sound in the upper midbass, midrange or treble frequencies are splashed around at playback time in the room's boundaries due to the loudspeaker's loss of polar control.
Listening to the Jubs over the past 10 years or so, I've found that that increasing the nearfield direct-to-reflected energy ratio significantly improves the experience of listening--for even poor recordings.
Chris
Here is the thread, but I don't think it will be all that helpful unless you have loads of time
http://forums.stevehoffman.tv/threads/platinum-shm-cds-launched.323981/
I say this because the forums there have very low SNR and the actual useful information is in the 5% range. Please feel free to message me if you'd like samples of any of these, I bought them for all the bands I was interested in and compared them to numerous versions (as well as emailed some of the mastering engineers who as usually forthright and happy to talk about their work).
Note that if the mixes are unbalanced sounding there is not a whole lot good mastering engineers can do to try and fix them, and the good ones I've spoke to pretty much leave them alone instead of trying to create huge boosts/suckouts in EQ.
I avoid remastered CDs as well, particularly those released by the major labels, these are often remastered in a way to sound good in car stereos or low quality headphones.
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13 hours ago, Chris A said:
I find that demastering dramatically increases the fraction of recordings that are worthy of listening to. If you are interested (and you have a setup that's been dialed in--including the room acoustics), then I've got examples that you can try out in A-B fashion.
Chris
For popular classic rock (ie Allman Brothers, Cream, Grateful Dead, etc) there are actually many audiophile versions of these albums on CD or SACD (with redbook layer) that are pretty damn close to flat transfers from the master tapes or only have 1-3 db of boost/shelf in some frequencies to massage errors in mixes according to the mastering engineers I've spoke to and they never use compression. There was also a series of CD/SACDs released by Universal Japan several years ago that were purely flat transfers of the master tapes with nothing else done to them, many popular classic rock albums were done in this series, there is a huge thread on the Steve Hoffman forum about them. In the liner notes they included the tape source (some albums have master tapes stored in the US some in the UK), mastering studio and mastering engineer name and a few of them verified that they didn't do anything to them per Universal Japan's wishes.
I will have a read through Toole again on reflections, guess I misremembered on when the reflections are happening.
With regard to surround, I would say at least 95% or more of the music I like is stereo mix only.
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Now this might be a controversial opinion but I think the vast majority of popular music (ie multi tracked rock, pop, etc) needs some help from early reflections to sound "good". Othewise you get a flat, forward image.
Where I loved the full Jubilee system I heard was with non-popular music (jazz, classical) that is well recorded where it truly felt like a live like experience from soft/small dynamics (I guess what audiophiles call microdynamics) to full scale dynamics. With this music the recording microphones have already picked up any depth/image cues so this doesn't need to be artificially painted with the speaker/room interaction.
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I have just ordered the third edition, the second edition served as a fantastic resource and I've gone back to it many, many times. IMO this is essential reading to anyone that is looking for high fidelity sound. It's also much cheaper than an AES subscription
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2 hours ago, DrWho said:
Hey jazz...
Have you considered an MTM alignment with the bass horn instead? Also, how much depth are you willing to go with?
I've been mulling over an 80Hz to 800Hz bass horn for a few years now and there's always something you have to give up if you want it to be a straight horn. The mouth area requirements for 80Hz make it real hard to get good vertical polars at the xover region - especially if crossing over to the K402. You would think you could undersize the mouth if the speaker is placed in a corner, but I haven't found a way to get the wavefront to align well with the room corner without folding the horn. If you don't align the wavefront, then you end up with early reflections from the corner that create large dips in frequency response at the lower frequencies (due to comb-filtering).
Going to an MTM alignment makes the mouth appear larger, and I've been experimenting with ways to use the vertical space to the sides of the K402 to augment loading into the room corner. I haven't found a great solution yet, but I'm still working on it. The interesting thing is that all methods to improve polar response cause the design to start looking closer and closer to Danley's synergy horns. I know Chris is really excited about the frequency response he gets out of his K402 with woofers bolted to it, but I'm not sure the K402 is providing much loading at the lower frequencies...it's been a while since I crunched numbers, but I want to say it was less than a 5% reduction in excursion for the same SPL (which isn't a large decrease in FMD). In other words, it's not much different than having normal direct radiators - the only real benefit is polar alignment. All that to say, I think it would make more sense to make a larger version of the K402 to provide the loading to an even lower frequency, and then port the woofers to reduce cone excursion as much as possible. Unfortunately this makes the xover to the subwoofers for 80Hz and below a lot more complicated due to all the phase happening. A larger K402 ain't exactly a walk in the park either...
Also, room modes start to dominate as high as 200Hz in some rooms - in which case I argue the location of the acoustic source is more important than polar consistency to the higher frequencies. (Thinking in light of the dual zoned bass array concepts). This has me returning to the MTM approach - but custom tailored to the dimensions of the room. Basically instead of avoiding early reflections at lower frequency, we can use the room as part of the wave guide....
Granted, these are all reasons why absolute perfection isn't possible - which we probably already knew. I think a split bass-horn in an MTM alignment can give very good results, and would be the best method to have the most control over the height of the tweeter. The only tradeoff is a notch in the far off-axis of the vertical polars, which shouldn't be very noticeable....certainly a lot less of an issue than the polar lobing that happens with the Jubilee LF. This approach will require a cabinet that is roughly 4ft deep if you want good loading all the way down to 80Hz...
I haven't considered this, I haven't looked into any K-402 replacement, right now it's basically what I'm "building around". I have a decent amount of space that I can work with, for instance 4 foot depth is quite manageable, I wouldn't really want to go deeper than that.
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7 hours ago, Bjorn said:
What would you choose a horn speaker like K-402 if you desire lateral reflections? A horn like K-402 minimizes side wall reflections with it's high DI. If you want lateral reflections, a horn is isn't the right choice and you might want to condsider a CBT speaker.
A traditional CBT speaker has a wide horizontal dispersion, avoids the floor bounce and minimizes ceiling reflections. FIY: I'm working on a CBT design with Don Keele.
Primary reason is I am really not a fan of the way they look
Second is I've heard the K-402/Jubilee in a rather live sounding room and absolutely loved the way they sounded, so this is a safer choice and I can mess around with diffusion or absorption at the side walls when I get to that point. For now the midbass horn/bass solution is most important.
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1 hour ago, Bjorn said:
Seems to me your best bet is to go with stacked woofers. Sealed enclosure will give you the smallest footprint. Well designed horn subs become big.
Toole and objective high fidelity; Does that go together?
IMO he advocates mediocre quality in every area. Speakers with serious vertical phase issues and quite high distortion, and poor acoustic environment with lateral high gain specular reflections. Not much high fidelity in that if you ask me.
Well I need to start somewhere, being an MD I don't have any engineering/professional audio background and I think him and Olive's papers/book are a good starting point. One specific area I do agree with him is lateral reflections adding to perceiving better sound. He is a primarily classical listener like myself and in my own experiences with all speakers (controlled directivity and not) these are desirable. And I think evidence from controlled blind listening tests are very important, which he has plenty of data on. No doubt there is still room for plenty of improvement which is why I didn't just go out and buy a pair of Revel Salons
The array sealed subs is also interesting. What do you think of PPSL?
Cost of drivers/building isn't an issue at all. I am really going for as few compromises as possible.
Back to the issue of tapped horn subs, the very small mouths on them for the low frequencies they reproduce has also been something that has bugged me.
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15 hours ago, Bjorn said:
I don't have experience with tapped horn subs myself but from what I hear from other that do, they don't seem to equal a front loaded horn in quality.
Personally I would go with a large front loaded horn or stacked 15" bass reflex subs. The latter equals a horn sub in quality when you have several, but the price is higher due to more drivers, cabinets and amplifier power needed to drive them. An advantage though is they can be crossed over high without any issues.
For front loaded horns these tend to become enormous (even say ones that load down to 50 Hz) unless you were thinking something like an array of multiple woofers horn loaded so the increased radiating area at the throat allows for a shorter length (ie pictures below if I didn't describe it correctly, I know these are more upper midbass type horns, just using them for illustration)?
I have no "as much horn loading as possible" dogma
I'm an AES paper/Toole fan just trying to put something together for music use only that is objectively high fidelity.
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11 hours ago, Bjorn said:
You can cross over as high as 120 Hz to a single bass unit without having it conflict with the stereo image in my experience. Perhaps slightly higher to, but around 150 Hz one either need two separate units close/behind the fronts or a single unit in the middle between the speakers.
It's also somewhat depended on how far it is from the mains. Placing it on the opposite side of the room to the mains would obviously not work well with a cross over at 120 Hz.
Do you think tapped horn subs on either sides (or behind) of the main speakers operating up to 100 Hz would be high fidelity? All of the ones I have looked at require a decent amount of EQ to flatten the response.
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On 12/27/2017 at 4:45 AM, Bjorn said:
The midbass horn I got designed would have to be deeper if it were to go lower. I didn't want to do that because:
1. The depth it requires.
2. I believe crossing over higher is really a better option in terms of quality. Both related to frequency response and distortion, a separate bass solution will perform better. And as a side-not; contrary to what many audiophiles believe, there's no reason to run stereo below these frequencies.
If we use the acoustic roll-over of the horn in the filter, around 90 Hz is about the lowest it can be crossed.
I personally don't think a dual solution is a very good option for something crossed over in the 450-600 Hz area. The drivers will not sum very well and create phase issues in what I consider to be a critical range. So if you desire to extend lower, I would simply increase the depth of the horn with a single driver. A simple straight horn will not minimize the floor bounce as the horn I have, and probably not have an equal uniform polar either but it will still work well.
I thought the research showed that bass localization couldn't be detected below 80 Hz which is why I set that as my cut off. If it's 100 Hz then that does make it much easier.
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Will give this a bump, and add a picture- visually this is basically what I am trying to achieve, a midbass horn that keeps the K-402 at a reasonable height. This is just for illustration only not to show the exact type I'm looking for. I don't think Tractrix or other rapidly expanding throat horn is the way to go for my application. This came up on a Google image search originated from this forum.
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There was some discussion about this in the "dissect polar patterns" thread.
Bass horns to operate below the K-402 beside the Jubilee bass bin for a couple of reasons.
To get the K-402 at a lower height to facilitate listening to the speakers closer and still get a point source image. There are a couple of designs that I can think of that do this and I think that 3 feet tall bass horn is a decent upper limit to shoot for. For instance Inlow Sound has a dual 15", 60 Hz straight horn that is 36x36 at the mouth and 48" deep.
And a horn that can match the wide polar pattern of the K-402 at its lower limit.
For me 60-80 Hz lower cutoff for the bass horn is fine because I will be using multiple tapped sub horns to fill in the bass below that as well as smooth in room response. And my preference is for straight horns to cover that critical 60-450 Hz region. @Bjorn created a 100 Hz horn that had very nice response, and started a thread about it, I'm looking for something that will extend lower.
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1 minute ago, Droogne said:
I dont mind derailing this thread, but I dont mind a more appropriate seperate thread either ofcourse. Makes it clearer for everyone!
It's fine, I'll start the thread if not tonight then this weekend. It's a different enough topic to warrant it. I see @Chris A has already touched on the Jub bass bin sitting a bit too high and I thought the same thing when I heard the full Jub/K-402 system.
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5 hours ago, Chris A said:
The short answer is "no", but such a bass bin design would probably look different--more like a University Classic design with one horn mouth instead of bifurcated into two horns with mouths side by side, or perhaps rather with the two bifurcated mouths fully rejoined together with a pointed nose like a La Scala bass bin.
Chris
Why would a design like this allow the bass bin to have wide coverage at say 450 Hz (using your steep crossover to K-402) and have the deep bass extension of the Jubilee bin? Maybe this is a discussion for another thread, hope the OP doesn't mind!
Actually I might start a thread on this in the technical discussion forum this evening.
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4 hours ago, Chris A said:
The polars on the Jub bass bin (KPT-KHJ-LF) in the horizontal direction get pretty narrow up around 400 Hz (anything above about 210 Hz)--much narrower than the K-402's ~110 degree coverage angle in that frequency band. That's what I was referring to. It's the main thing that the K-402-MEH prototype showed me in terms of listening differences between it and the Jubs, as well as coherent point source in that same frequency band. The listening difference: clarity/speech recognition, and general midbass presence. It's clearly different, in fact.
Chris
Wouldn't it be pretty difficult to design a bass horn that extends as low as the Jubilee bass bin that would have wide pattern control at the lower limit of where the K-402 is crossed over?
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1 hour ago, Droogne said:
I believe a lot of comparison were made between the Seos 24 and the K-402, but not with the (I think more recent) Seos 30. Not sure. Pair of black painted Seos30 with good drivers (HF200 from faital) would only cost me 1050eu. Still hoping to find a dealer to know the price for the K-402 (incl. all the shipping etc) so I know what I'm up against! To be clear: I'm 100% planning on buying the K-402, but depending on cost I might go for an intermediate. And before you say "that's gonna cost you more in the end", well that's true. But, I also have LaScalas for the rear and side (and center), and if the 2-way is something I like I could move the Seos to the rear/side when I decide to go for the K-402. Seos would be easier to have as a center too due to it's height (10cm). But who knows what I can come up with (rising the couches so the tv height isnt an issue anymore)(K-402 mounted above the tv? with bassbin beneath it, or to the sides?? )(synergy K-402? Not sure I have the skills to pull that off)(Seos as a center between K-402 rears, not sure about timbre matching, but who knows how good it turns out if I'd use the same driver as the K-402 + EQ)(insert random idea)
Personally I would only do a setup where the K-402 sits above the bass bin or horn to get the most coherent point source image.
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@Chris A what is the lower limit that you run your TAD drivers at and what sort of a crossover slope does it use to the Jubilee bass bins?
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I will suggest asking at Headfi since Moth Audio made many headphone amps, so there might be some owners that have their speaker amps over there.
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How to dissect polar patterns and frequency responses for horns.
in Technical/Restorations
Posted
The top ones look like they were done by Harman.