[Berlioz]

My friend got a Phonitor recently so I went over to check it out. I've been looking at tube amps up until now, but I was very impressed by the Phonitor's crossfeed ability (not sure if that's the correct terminology).

I really enjoyed the option to change the speaker angles and such, and from what I've read, no other amp approaches it's performance in this regard. Also, because of it's considered such a high level amplifier (for now, anyways), it's likely this would be the only headphone amplifier I'd own for a long, long time.

The problem is, I really want to try a tube amp, because I'd like to experiment with tube rolling, and I really don't mind the warmer sound. I've been looking at some very clean tube amps, like the DNA Sonett, and I was quite set on one before running into the Phonitor.

So I'm basically just asking for opinions on the issue. Can I get the best of both worlds? Should I just get a tube based DAC if I want to experiment with tubes?

Also, I see balanced XLR inputs are standard on the Phonitor. My CDP will be using unbalanced RCA outputs. On the forums I've read that you can get a RCA to XLR cable, but people have mentioned you need to re-wire it. I looked at the diagram SPL provided on what to do, but I have no idea how do any of that. Is it possible to get pre made RCA to XLR cables that satisfy the requirements, or is that even necessary?

 

[atothex]

What do you mean best of both worlds? I'm assuming you mean clear and powerful amplification? My personal opinion is that any good amp will sound clear and detailed. The bad stereotypes for tube/SS only apply to bad amps.

 

[Berlioz]

Thanks for the reply. By best of both worlds, I only meant being able to tweak the crossfeed but also having some tube component in the system that I can swap tubes out of.

 

[XXII]

I would go for a tube DAC.

You can just order a RCA->XLR cable from BlueJeansCable or buy a RCA->XLR converter.

 

[Covenant]

Which then begs the question, which tube DAC? I don't know if I'm entirely sold on tube dacs IMO, as any distortion introduced by the tubes in the output stage would just be amplified by the Phonitor.

The virtue of a tube amp is in its distortion, creating a more analogue style of presentation and a certain elasticity of soundstage that solid-state finds hard to replicate. But these "colourations" are best kept to a minimum, IMO, to make the effect subtle and subconsious, rather than glaringly "tubey". Following a tube DAC with a highly linear, revealing solid state amp strikes me as working contrary to this.

Just my 2c.

 

[jojo_b2]

A tube DAC would be a good Idea. But from what I was able to try before a Tube Pre-amp usually spells alot of difference to my ears anyway. Some used tube preamps are going cheap. This might help you balance out the money you will use for purchasing your equip specially if you already have a good CDP or DAC in hand. =)

 

[Berlioz]

Is it possible to hook up a tube preamp to the Phonitor? I'm sorry if that's painfully obvious; I just have no idea how the electronic connections would work.

 

[Uncle Erik]

First, you can buy or make a standalone crossfeed unit if you want crossfeed. I have Dr. Meier's Corda Cross I, and while I don't talk about it much, it's one product I've used consistently over the years. It's out of production, but plans are available at his site. There are other crossfeed plans at Headwize and HeadRoom's amps offer crossfeed, too.

If you want a tube amp, don't get one for experimenting with tubes.

I'll draw fire for this, but tuberolling has always seemed pointless to me. Sure, different makes sound slightly different. However, tubes change in value over time, so all the talk and hype is sort of like describing a river flowing by minute by minute. It's never the same twice.

What's important to me is find a tube that works. If it does and it sounds good, I'll use it until it dies. I don't want to repeatedly swap out tubes and scrutinize minute details and post impressions. If that's your thing, OK, but I'd much rather spend my time deeply involved in the music than putting something that's going to change anyway under a microscope for an ephemeral impression.

Anyhow, if you want the sound of tubes, just get a tube amp. If you're drawn to the traditional tube sound, then find triodes fed to output transformers. That's where most of the sound is. Also pay close attention to the construction of the power supply. This is where a lot of inexpensive amps get cheap. Everyone focuses on the tuberolling capabilities, but the power supply is more important.

 

[onocentaur]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif First, you can buy or make a standalone crossfeed unit if you want crossfeed.

+1, also, Dr. Meier will soon be releasing the StageDAC with adjustable crossfeed. I'm sure the DAC will be top-notch, and I for one am very much looking forwards to being able to use an improved Meier crossfeed with a variety of amps... not that the Corda amps are anything but excellent

 

[Leonardo_BVB]

Dear Berlioz, you have a couple of very simple options in order to get the best of both worlds:

1. Get a buffer tube preamplifier. It is a simple "box", normally with 1 input and 1 output that "filter" the music through the tubes (normally triodes). You do not need a full pre-amplifier for what you want (but you could, of course also go for that option). I have the Icon Audio BA2 Musical Box and it uses 6sn7 valves that you can very easily swap should you wish (have a look at: Icon Audio Leicester UK (Product Gallery) ). There are other companies that do buffers like Musical Fidelity, etc (there are also cheap alternatives on e-bay valve buffer, Consumer Electronics items at low prices on eBay.co.uk ). The procedure is simple: You hook the CD player to it with normal RCA cables an from it to the PHONITOR with RCA to XLR cables. You can buy them terminated in many places ( 0.5m Neutrik Van damme XLR-M to Phono Cable on eBay (end time 08-Aug-09 22:58:42 BST)) or simply buy a RCA to XLR adaptor and use normal RCA cables (like this Neutrik NC3MXX-B XLR-M Black & Gold Male XLR Connector on eBay (end time 18-Aug-09 20:59:22 BST)).

2. You will need a DAC that allows you to use CROSSFEED and, as far as I know only the incoming STAGEDAC from Meier audio or the Lavry DA11 can do that. You just connect through RCA wires the DAC to the tube headamp of your choice and off you go!

I am waiting to buy the STAGEDAC but, for a while, I considered very seriously purchasing a Phonitor and use it with my Icon BA2. The thing is, I am very happy with my Grahan Slee/BA2 conbination so, the STAGEDAC will give me the only feature I am missing: the crossfeed.
Yours

 

[suikodenii]

FWIW, different implementations of crossfeed not necessarily equal each other.
I had the 2Move from Meier Audio with Crossfeed and it is not at all comparable to the Phonitors crossfeed/speaker angle features.
The Meier Audio crossfeed is very good for removing listening fatigue common with strong stereo separation.
However the Phonitor seems unique so far in actually pushing the soundstage in front of you, plus the option to alter the soundstage width according to the speaker angle setting. All this at zero expense to sound quality, at least to my ears.
I haven't heard any other implementations of crossfeed yet (like Lavry's), though. I suppose that over time other comprehensive options will become available in s/w in case you will use a computer as source.
However if you want to have a stellar amp and a well working implementation of crossfeed in a tight package that can be used with any source then I'd say have a close look at the Phonitor and try it with different sources to see if you can get the sound you want.
Which source has been used in the session you had with the Phonitor by the way? I use the PS Audio DL3 (stock) w/ the Phonitor and find the sound to be slightly on the warm side of neutral. I am sure other sources - even SS - can alter that to even warmer sound should you prefer that.

My 2 cents

 

[Berlioz]

Thanks for all of the responses. I now understand how to deal with the RCA to XLR issue. It seems that all I have to do is send the wiring diagram to a cable manufacturer and they will make the right converters for me. Also, the 2 pin - hot configuration that SPL uses is the most common one anyways.

As for the amp issue, I understand what I need now, although I'm still a little undecided as to what I want. I was thinking of going for a Lavry DA10 for the DAC. It looks like an excellent DAC that will hold it's own for quite a few years, and it's got balanced outputs so that solves my other issue. It's bigger brother, the DA11, has a crossfeed ability, but I seriously doubt that it's comparable to the Phonitors.

I'll be running the DAC from a professional CD player I recently bought. It's pretty sweet for a transport, and I hope to be doing a review on it soon.

The tube buffer seems like a great idea, but I just want to make sure that the buffer wouldn't harm my equipment in any way. Obviously if a tube goes, then it will, but will switching from a low imp headphone to a high imp headphone possibly blow a diaphragm (without turning the system off, first)? Sorry if that's a stupid question. Also, I usually see that the word "buffer" carries a negative connotation. Is it going to seriously degrade the sound, or just add in some warmth (like I hope)?

I REALLY wanted the Sonett, but I tried the Phonitor out again and well, the crossfeed is just too cool. It's a handsome amp as well, and it's got some heft to it. Looks like my entire setup (transport, DAC, amp) will be composed of pro audio gear. It seems very few go down that path on Head-Fi, but I know I'll get back with some reviews on what I think of it!

 

[USAudio]

Quote:

Originally Posted by Berlioz /img/forum/go_quote.gif ... It's bigger brother, the DA11, has a crossfeed ability, but I seriously doubt that it's comparable to the Phonitors. ...

FYI - The DA11 PiC feature is done in the digital domain with no additional noise, compression, loss of resolution, etc.
Additional details here:
http://www.lavryengineering.com/whit...s/DA11_PIC.pdf

 

[Leonardo_BVB]

Quote:

Originally Posted by Berlioz /img/forum/go_quote.gif Thanks for all of the responses. I now understand how to deal with the RCA to XLR issue. It seems that all I have to do is send the wiring diagram to a cable manufacturer and they will make the right converters for me. Also, the 2 pin - hot configuration that SPL uses is the most common one anyways. As for the amp issue, I understand what I need now, although I'm still a little undecided as to what I want. I was thinking of going for a Lavry DA10 for the DAC. It looks like an excellent DAC that will hold it's own for quite a few years, and it's got balanced outputs so that solves my other issue. It's bigger brother, the DA11, has a crossfeed ability, but I seriously doubt that it's comparable to the Phonitors. I'll be running the DAC from a professional CD player I recently bought. It's pretty sweet for a transport, and I hope to be doing a review on it soon. The tube buffer seems like a great idea, but I just want to make sure that the buffer wouldn't harm my equipment in any way. Obviously if a tube goes, then it will, but will switching from a low imp headphone to a high imp headphone possibly blow a diaphragm (without turning the system off, first)? Sorry if that's a stupid question. Also, I usually see that the word "buffer" carries a negative connotation. Is it going to seriously degrade the sound, or just add in some warmth (like I hope)? I REALLY wanted the Sonnet, but I tried the Phonitor out again and well, the crossfeed is just too cool. It's a handsome amp as well, and it's got some heft to it. Looks like my entire setup (transport, DAC, amp) will be composed of pro audio gear. It seems very few go down that path on Head-Fi, but I know I'll get back with some reviews on what I think of it!

Dear Berlioz, there are not stupid questions, only stupid answers!
Regarding your doubts about the buffer preamp, there is nothing for you to worry about, thermionic valves do not operate in the same way than normal bulbs. Basically, the valve consists of a hot emitter electrode from which electrons are vaporized by thermionic emission and a colder collector electrode (getter) into which they are condensed after conduction through the interelectrode plasma. The resulting current, delivers electrical power to a load at a typical potential difference of 0.5–1 volt and thermal efficiency of 5–20%. So in plain English you put a current through the valve and a modified current gets out with a thermal loss as a by product (heat). If the valve fails, no current goes though. As simple as that, no explosions or anything spectacular like sometimes happens with normal bulbs. Bare in mind also that any decent valve design will have safety mechanism for short circuits, like your other components so you should be safe as long as they are operating within their tolerance limits. I personally switch the valves 5 minutes or so before I switch anything else to give time to warm up. It is true that they sound at their best after 30 minutes or so, specially if they are from the forties like the VT-231s that I am using at the moment. If you have the headamp switched before you connect your valves you will have a "pop" sound in your headphones and that's about it, no major problems.
The name "buffer", in my opinion, is used because it goes between two components, not because it's suppose to create a "safety barrier" between them.
The change they produce in the sound is truly significant and they do enhance the "analog feeling" making it sound more natural. I love Miles Davis and, without the valves, his trumpet sound harsh even from SACD but, with the valves, it does sound mellow and natural, and it is an absolute pleasure to listen to through headphones. The valves introduce harmonic distortion that is very agreeable to my ears and pretty much to anyone's ears. The changes are far more evident when you listen through headphones. The best part is that you can tailor the sound to your taste with different valves (I have a collection now!).
I have attached a picture of my headphone system so you can see how it looks.

 

[Uncle Erik]

Why add needless components to a system? I "get" the point of a buffer adding tube characteristics to the sound, but I don't "get" why you would buy a buffer instead of just using a tube amp in the first place. Buffers seem to be completely pointless products.

Further, every bit of equipment you run the signal through degrades the sound. Every extra tube, every extra capacitor, everything, takes a little something away from the signal. Why add more?

If anything, you want to minimize the amount of parts the signal has to pass through. Like so many things in life, you want to use the fewest parts of the highest quality. Here's an amp I'm building:

As you can see, the attenuator connects right to the tube, which is hooked to the output transformer. There's one resistor and one cap going to ground. That's it. That's all you need.

If you want the best sound, then you should use the fewest parts of the highest quality. You're not going to get that by adding yet another box to the signal chain.

As for the Phonitor's crossfeed - I think this is more signal processing than actual crossfeed. I'm not much of a fan of signal processing, either. It never sounds natural. A little subtle crossfeed can help, but outright signal processing is a gimmick. No thanks.