taboo

[Duggeh]

I'm a mod there as well. At least I was last time I logged in.

[deepak]

Isn't the forum more of a joke where PinkFloyd can stroke his own ego...

[spritzer]

Isn't the forum more of a joke where PinkFloyd can stroke his own ego...

...and HF is???

[tyrion]

...and HF is???

a place where you can stroke yours.

[deepak]

...and HF is???

Headfi doesn't have rickmonster any more

[spritzer]

a place where you can stroke yours.

I guess I'm doing that by warning people off overpriced crap...?

Headfi doesn't have rickmonster any more

I do miss the guy sometimes. He took drunk posting to a whole new level...

[tyrion]

I guess I'm doing that by warning people off overpriced crap...?

I do miss the guy sometimes. He took drunk posting to a whole new level...

Like I said, some people would call what you are doing a troll. WTF made you the guardian of what is and isn't junk. If you have an opinion, say it, but back it up with fact or a basis so you don't come off as a troll.

[spritzer]

Like I said, some people would call what you are doing a troll. WTF made you the guardian of what is and isn't junk. If you have an opinion, say it, but back it up with fact or a basis so you don't come off as a troll.

So stating that the amps are badly built is trolling where I know of at least two amps that went up in smoke? Add to that, that the basic circuit is a relic that Rudi doesn't even understand and using 12AX7's to drive EL34's was one of those things that gave tube amps such a bad rap back in the tube vs SS wars. It was posted that this was the ultimate amp just because it costs so much and I posted that it didn't have any ultimate amp potential. It's my experience that Rudi, just as Ray, is one of those "designers" that has something to hide.

[tyrion]

Just coming into a thread and posting something is a POS without having seen the amp, heard the amp, looked inside the amp. And having done none of the above, not state the basis for your opinion. KG expressed an opinion about the amp and stated his basis for the opinion.

[kevin gilmore]

here is my opinion on that OTHER site. Wonder how long it will last.

Actually my take on this amplifier is a bit different given hints from

rudi's website. If you believe the distortion numbers rudi quotes then

clearly there is significant feedback in the amplifier. Therefore

each of the 4 output sections is likely to be a composite amplifier

with 1 section of a 12ax7 triode connected to a el34 wired as a triode

with feedback around this section.

Then the input is rudi's unbalanced to balanced autoswitching balanced

to balanced input stage which is all opamps.

If you look at the amp chassis however, there is no indications of

any external heatsinks. If you run the el34's at their sweet spot of

about 10 watts each, then somewhere there is going to be plate

resistors or constant current sources that dissipate 40 additional watts.

If that is inside the chassis as it certainly has to be the thing is going

to get very hot.

Probably the best thing rudi has done to date. Certainly the most expensive.

There were a few burmeister electrostatic amps built, they were $25k each.

Evidently they were worth it.

__________________

Quando Omni Flunkus Moritati

Now the stuff that would be deleted over there...

No more box of boxes, i'm disapointed.

limited to 400vrms HOW??? And why would you anyway.

And if it can do 700vrms is that stator to stator, or stator to ground.

Notice the low frequency cutoff is 2 hz. Yeah bullshit, and it also means

its a capacitively coupled output. Back to that correct spectral harmonic compensation

thing (politically correct version 3)

[spritzer]

Just coming into a thread and posting something is a POS without having seen the amp, heard the amp, looked inside the amp. And having done none of the above, not state the basis for your opinion. KG expressed an opinion about the amp and stated his basis for the opinion.

That is a fair point but I have seen the amp and drawn my own conclusions from that based on my knowledge of the subject matter. While Kevin will have a better idea what's going on there I have done my fair share of amp building and know enough to see that something is missing like the heatsinks that should be present. I tend to be a little harsh but thats just because I'm saddened by the state of HF today, all new things are great and there are no in depth discussions about anything, any more. If it wasn't for the Stax threads I'd be long gone...

[tyrion]

That is a fair point but I have seen the amp and drawn my own conclusions from that based on my knowledge of the subject matter. While Kevin will have a better idea what's going on there I have done my fair share of amp building and know enough to see that something is missing like the heatsinks that should be present. I tend to be a little harsh but thats just because I'm saddened by the state of HF today, all new things are great and there are no in depth discussions about anything, any more. If it wasn't for the Stax threads I'd be long gone...

I don't care what the opinion is one way or another. My gripe isn't about that. It's about expressing and opinion about something without hearing it, seeing it, opening it, etc. If, like KG, you can do that without the above based upon your knowledge and expertise, fine but to just say something is a POS, is wrong.

[kevin gilmore]

I'll add that it can't meet the gain and distortion numbers if it is only the 2 tubes in the

audio circuit. At most you are going to get a voltage gain of 100, and you really need

a minimum of 500, and really 60db which is 1000.

[spritzer]

I don't care what the opinion is one way or another. My gripe isn't about that. It's about expressing and opinion about something without hearing it, seeing it, opening it, etc. If, like KG, you can do that without the above based upon your knowledge and expertise, fine but to just say something is a POS, is wrong.

I can just do that to some extent at least. By looking at a design you can make some observations such as with tube choice, heatsinking, the amps size etc. It is the same with the HEAudio phone as I can see a number of issues just by looking at them and those are confirmed by the feedback I got. I might buy them as a little project but I'm committing all of my audio funds to upgrade my main system and find those damn few remaining Stax headphones I lack for my collection.

I'll add that it can't meet the gain and distortion numbers if it is only the 2 tubes in the

audio circuit. At most you are going to get a voltage gain of 100, and you really need

a minimum of 500, and really 60db which is 1000.

There is some BS about "...that assisted by some solid state components (in order to control some auxiliary functions)..." so that could be the opamp first stage but that wouldn't provide any gain, right? The gain is quoted at 65dB's but the talk of an all tube amp makes the numbers look a bit "doctored".

[kevin gilmore]

Of course the numbers are doctored. I've yet to test a rudistor amp that

comes within 30% of rated specifications. Same thing with the complete

bullshit numbers on the apache.

>120db signal to noise ratio. Absolutely impossible with an amplifier with

a gain of 65db. Fact is even under the best conditions, johnson noise will bring

the signal to noise ratio down to about 108db. Unless of course you plan on

running the thing in a bath of liquid nitrogen.

2hz. Again absolute bullshit. Those chassis are what about 1.5 inches thick.

Output caps big enough to give 2 hz frequency response would be bigger around

than the chassis depth. Or really shitty electrolytic caps.

How about that power supply. Anyone see any chokes on the top of that supply.

They sure aren't going to fit inside the case. Which means that if the supply

is actually regulated, then it is solid state that is doing the regulation. Completely

ass backwards. You might want solid state rectification, but you want a pass tube

for the power supply if what you are after is the tube power supply sound.

Rudi's opamp unbalanced/balanced to balanced input stage has a gain of 13db.

At least the version in his latest dynamic amp does. All the voltage gain in that

amp is all in the cheap opamps.

It may be built better (because its actually built in the UK) than the old junk, but

it is still a piece of shit. A very expensive piece of shit. Somebody will buy one

sooner or later, then we will get pictures of the insides.

If rudi is not showing pictures of the insides like he has done with some of his other

units, you know there is a reason.

[spritzer]

Thanks for a great reply and answering those doubts I had. I don't think he could have fitted any chokes in that tiny PSU chassis or any decent quality electrolytic caps (Black Gate, Mundorf, Siemens, Jensen, Nichicon etc.) let alone PIO's. Then the PSU is only meant to look impressive to gullible individuals that believe the sales pitch. It's to bad that isn't exactly rare these days.

If he's electrolytic's as output caps he should be put on trial as the opamps are bad enough.

I'm sure somebody will buy one of these and rave about how great it is... after all it must be since it cost so much...

[postjack]

I come from HF too, but I've noticed that most members here are so experienced that almost none of you will be interested in low to mid-fi gear which I can afford. Many of you have beta22, northstar, L3000, few R10s.....

Sure, but a lot of us have tried tons of the mid-fi gear, so please feel free to ask questions and we'll be happy to answer. And I for one am always happy to read about budget gear, since we never know when we'll find ourselves in a situation where downgrading becomes a necessity.

[hYdrociTy]

I come from HF too, but I've noticed that most members here are so experienced that almost none of you will be interested in low to mid-fi gear which I can afford. Many of you have beta22, northstar, L3000, few R10s.....

lies i have low end gear let's chat.

[Anders]

I wondered if really ALL references to Head-Case are deleted from Head-Fi so a while ago I mentioned Head-Case in a thread, in adequate context and not at as a flame war. It took only a few minutes until the post was edited and Head-Case deleted. I can understand that Jude dislikes this site but this taboo is going too far.

I have some questions about amplifier design. I have very little knowledge in the field except some understanding of common terms. I am surprised about all the discussions on inferior design because amplifier design should be a well developed field of knowledge - at least as long as we restrict as too mid-fi and a bit up - maybe not the state of art. Could it really be a problem to make a good design of an amplifier for an engineer with expertise in the field? I thought that the real problem in manufacturing and business is to implement the design i a way that is cost-effective and develop effective marketing and distribution. Of course it takes time, but not really a technological problem.

It seems that design and manufacturing of headphone amplifiers often are poor with bad principal design, low production standard and problems with reliability. Experienced DIYers can be more knowledgeable than commercial designers. Is the problem that production of headphone amplifiers to a major extent is an outgrowth of DIY and that not always the most suitable choose to start a business? Is headphone amplifiers a profitable market or are there simply too many enthusiasts? In my experience, it is very difficult to find adequate information as a ground for decisions on purchase. This situation is not unique for headphone amplifiers but I think it is worse than for other audio components.

[Fitz]

lies i have low end gear let's chat.

You own shitty gear just so you can hit on teh noobs.

[Mastergill]

Is the problem that production of headphone amplifiers to a major extent is an outgrowth of DIY and that not always the most suitable choose to start a business? Is headphone amplifiers a profitable market or are there simply too many enthusiasts?

Yes and yes.

Problem is most headphone enthusiasts are new to the audio hobby and make easy prey for unscrupulous amateur amp builder.

It's much easier to start with speakers as there's a lot of good established company with decades of experience and feedback from experienced users too.

[deepak]

It's much easier to start with speakers as there's a lot of good established company with decades of experience and feedback from experienced users too.

Yet they too might be using shitty and cost cutting designs.

[aerius]

Yet they too might be using shitty and cost cutting designs.

The great thing about diyAudio.com is that there's boatloads of information and in-depth technical discussions with lots of highly knowledgeable people. The bad thing is after a year or two there, you come to realize that many commercial products are pure utter shit.

[spritzer]

The great thing about diyAudio.com is that there's boatloads of information and in-depth technical discussions with lots of highly knowledgeable people. The bad thing is after a year or two there, you come to realize that many commercial products are pure utter shit.

It's the sad, sad truth. All the gear I lusted after when I started this collective insanity of ours has turned out to be crap design with a fancy faceplate. It's ok to have a less then stellar design or cut some material corners when you are competing in a very tough price bracket but cutting corners on a cost no object design is criminal. Small things like PCB mounted connectors and jumpers are an eyesore when we are talking about reference level.

[deepak]

It's compounded by the fact that nearly every audiophile forum (including speakers) is so over moderated that people don't post about gear that sounds bad, give it undue praise for no reason or feel some need to believe that manufacturers are their best friends and don't want to say anything bad about their products.

diyaudio is definitely a haven for good info, and I'm trying to wrap my head around it all.