[Argo Duck]

V-Duh, great table!

 

[WNBC]

I think you make a very fair point about headphones that are very efficient.  However, people are noticing problems are using planar type headphones that were designed for the Taboo.  The hum in my Taboo is not as bad as others but I would not use new lucid mode because of it.  With old lucid mode not so bad.
 
This is straight from Decware website:
"ULTRA LOW NOISE - Less than 1 mv of noise and hum (usually 0.4mv). The benefit is ultra black backgrounds and inaudible hum on even the most efficient ear speakers."
   
 
 
Quote:

I was very surprised when Frank Iaccone and later Eric (longbowbbs) used the Taboo III (very successfully I would add) with the Senn HD800! Yet, such phones were not its intended application. IMHO it is simply not fair to rate a piece of equipment on applications outside its design envelope.

However, it would seem Steve hasn't said to you 'you should not use this amp with the HD800'. That in itself would seem to indicate de facto acceptance on Steve's part of how the market is using his product. Nevertheless, should we be surprised if problems arise with phones other than those for which the amp was designed?

 

[dan.gheorghe]

Ok, if we're talking about the Taboo mk III, Steve's thread about the how and why he decided to design a new Taboo (see here) makes its target headphones crystal clear. In his own words: "the new TABOO amp...was re-designed to be the best sounding amplifier for the LCD-2's and similar headphones.". I'm not sure what you mean by "Decware didn't test their amps with more headphones" but I think as a reviewer you need to be aware of the Taboo's intended application and you will find that thread interesting background information too. (You can find the information about what phones the Taboo III was designed for in the Decware marketing as well).

For other headphones, the CSP2 (now 3) has always been recommended.

I was very surprised when Frank Iaccone and later Eric (longbowbbs) used the Taboo III (very successfully I would add) with the Senn HD800! Yet, such phones were not its intended application. IMHO it is simply not fair to rate a piece of equipment on applications outside its design envelope.

However, it would seem Steve hasn't said to you 'you should not use this amp with the HD800'. That in itself would seem to indicate de facto acceptance on Steve's part of how the market is using his product. Nevertheless, should we be surprised if problems arise with phones other than those for which the amp was designed?

Which I guess begs the obvious question: Dan, have you encountered these problems with your LCD3/LCDX? (Apologies if you've already addressed this - my following of head-fi is highly fragmented these days!)

 
I have encountered the problem with LCD-X, which doesn't need as much power as lcd2 or lcd3. However it is still an audeze headphone ... and still planar and makes use of power quite nice. As I have stated before...the hum is only in one channel. That shows that something is not symmetrical somewhere in the circuit showing a design flaw maybe...(as I am not the only one having it, it seems)
 
Making an amp just for 2 headphones....not a good idea... Audeze released a new headphone..ok...must get another amp...(i don't think so). And as a reviewer...well... I must see this as a con...
 
And I am not speaking here about IEMS or portable headphones...as indeed I haven't bought taboo for that...

Originally Posted by V-Duh /img/forum/go_quote.gif
 

 
Dan,
I'm afraid I have virtually the same problem.  I received my amp last April but did not notice a problem until this fall because I was only using my Senn HD600 and AKG 702.  I tried my Grados in mid-November as someone mentioned decent synergy and I was immediately faced with a significant hum and a weird fluctuating static/wooshing sound primarily in the left channel.  I assumed EMI and planned to track it down when I had time.  Meanwhile I received my LCD-X, plugged it in and "AACK! This kinda sucks."  Eventually I had time to try a bunch of things and all my cans resulting in the development of the table below.  It appears to be very similar to your experience.  I sent this information to Steve and his initial impression is there may be a grounding problem resulting from shipping.  I will be sending my amp to him for diagnosis once I can get out from under all the holiday responsibilities.  I will report on any findings.

Thanks V-Duh. Waiting for your results!!
 
Ah and PS... I don't want the hum to disappear on lucid modes...as I don't use them. I just want to make it disappear on the default mode.

 

[longbowbbs]

I was very surprised when Frank Iaccone and later Eric (longbowbbs) used the Taboo III (very successfully I would add) with the Senn HD800! Yet, such phones were not its intended application. IMHO it is simply not fair to rate a piece of equipment on applications outside its design envelope.
 

I would not have purchased the Taboo Mk III if I had not heard it first with the HD800's. Since Steve specifically spoke of the LCD-2's as his HP Standard, I was curious about the HD800's. I already had the CSP2+ and it was a great match. Steve's expectation was that the combination would have more body and heft (it did) so I ordered the amp after I listened to it. I think I was the first person to have heard the Taboo MK III other than Steve and the first to hear it with the HD800's.
 
I would have it today if the opportunity to acquire the SLI-80 had not come along. The Cary is a long time aspirational piece for me. The Taboo is a great amp both for speakers and HP's. Fortunately, I never experienced the hum people have been experiencing.

 

[Argo Duck]

Dan, fair points, except I think by "LCD2's and similar" Steve meant orthos in general (but not the HE6), not the LCD2 in particular. I guess the point about Decware power amps is they were designed to be speaker amps. Then Skylab (with the Mini-Torii) and Frank I (the Taboo) asked for speaker jacks and suddenly they were hp amps too. I suppose one might now debate the wisdom of this move without having specifically tested and designed for headphones.

OTOH, the long-time pre-amp and hp-amp the CSP2 and 3 seem to have been more generally successful and robust.

WNBC, absolutely fair point. What you quoted is impossible to dispute!

Eric, thanks for that piece of history. I frankly couldn't remember whether it was you or Frank who tried the HD800 first. Clearly it was you, and equally clearly Steve was happy to see the Mk III used this way.

Well, we've been here before., e.g. questions over QA (sigh). Decware is a small company with a hugely talented, creative designer. Unfortunately, it's not a company with resource to test product reliability over widely varying conditions. I'm not blaming those of you who may have these hypothetical problem conditions, merely speculating about why there may be a design flaw which the company's normal development, testing and QA hasn't revealed. Unfortunately, such things happen. Even in well-resourced companies.

It's easy for those like me who are problem-free to stand on the sidelines, scratch our heads and say "but these products are great!". I feel for you guys

 

[Kendoji]

FWIW mine hums with my orthos too.

 

[longbowbbs]

Dan, fair points, except I think by "LCD2's and similar" Steve meant orthos in general (but not the HE6), not the LCD2 in particular. I guess the point about Decware power amps is they were designed to be speaker amps. Then Skylab (with the Mini-Torii) and Frank I (the Taboo) asked for speaker jacks and suddenly they were hp amps too. I suppose one might now debate the wisdom of this move without having specifically tested and designed for headphones.

OTOH, the long-time pre-amp and hp-amp the CSP2 and 3 seem to have been more generally successful and robust.

WNBC, absolutely fair point. What you quoted is impossible to dispute!

Eric, thanks for that piece of history. I frankly couldn't remember whether it was you or Frank who tried the HD800 first. Clearly it was you, and equally clearly Steve was happy to see the Mk III used this way.

Well, we've been here before., e.g. questions over QA (sigh). Decware is a small company with a hugely talented, creative designer. Unfortunately, it's not a company with resource to test product reliability over widely varying conditions. I'm not blaming those of you who may have these hypothetical problem conditions, merely speculating about why there may be a design flaw which the company's normal development, testing and QA hasn't revealed. Unfortunately, such things happen. Even in well-resourced companies.

It's easy for those like me who are problem-free to stand on the sidelines, scratch our heads and say "but these products are great!". I feel for you guys

Frank received the first shipped unit of the Taboo MK III. I listened to the prototype that Steve used to voice the amp. (Mine was Ser # 10) When Steve listened to the amp with my HD800's it was the first time he had put a pair of HD800's on in his life.

 
Remember he is also a speaker designer. Head-Fi is a newer focus for him. Frank and Rob (Skylab) really got him into the game with the Taboo (Frank) and the Mini-Torii (Rob) Each asked him to put a HP jack on their respective amps.
 
I will likely buy another amp from him. I had terrific service and I loved the amps.

 

[ZenTriode]

 
I did in fact design the Taboo MK III for the LCD2 and LCD3 headphones.  These hard to drive planar headphones deserved a purpose built amplifier because of both their fidelity and popularity.  
 
We already make a great OTL headphone amplifier/preamp that is ideal for use with regular headphones. (CSP3) And there was no LCDX at that time.
 
In my writing about the Taboo MK III and new lucid mode, I made it pretty clear that the effect is tied to impedance.  The LCD's were in the 50-70 ohm range where new lucid mode was carefully voiced.  On speakers or other headphones the new lucid mode would be exaggerated or reduced from that ideal.
 
That said, many people use the Taboo MK III on a variety of different headphones and I’m fine with that so long as the above is understood regarding the new lucid mode.
 
I will be adding a custom option to the shopping cart for the Taboo MK III that will allow the buyer to select from standard gain and low gain.  Low gain being for more efficient non-targeted headphones.  If 4 pin jacks are selected we could make one high output and one low output as well.
 
This could technically be done externally if the right resistors were used.
Mouser # 71-CW005150R0JE73 which is a 150 ohm exactly matches what’s on the inside.  You could go as high a 1K with some phones or IEMs.
 
As for hum on one channel only:
 
Since the internal layout is not perfectly symmetrical, the noise floor is going to be louder on one side over the other.  This is true of most audio gear, once you magnify the noise floor.  Even if both sides were exactly the same layout, differences in tubes would be heard, so the real issue is hearing the noise floor at all.  With 1700 Miliwatts of output, anyone hearing hum has more than enough volume left on the dial to hurt themselves.  That means that for headphones that you hear hum with, there is too much gain or power.  Reducing it will give you more usable range on the volume control and reduce the hum by an equal amount.
 
 
 
Hope this helps!
 
Steve Deckert

 

[dan.gheorghe]

   
I did in fact design the Taboo MK III for the LCD2 and LCD3 headphones.  These hard to drive planar headphones deserved a purpose built amplifier because of both their fidelity and popularity.  
 
We already make a great OTL headphone amplifier/preamp that is ideal for use with regular headphones. (CSP3) And there was no LCDX at that time.
 
In my writing about the Taboo MK III and new lucid mode, I made it pretty clear that the effect is tied to impedance.  The LCD's were in the 50-70 ohm range where new lucid mode was carefully voiced.  On speakers or other headphones the new lucid mode would be exaggerated or reduced from that ideal.
 
That said, many people use the Taboo MK III on a variety of different headphones and I’m fine with that so long as the above is understood regarding the new lucid mode.
 
I will be adding a custom option to the shopping cart for the Taboo MK III that will allow the buyer to select from standard gain and low gain.  Low gain being for more efficient non-targeted headphones.  If 4 pin jacks are selected we could make one high output and one low output as well.
 
This could technically be done externally if the right resistors were used.
Mouser # 71-CW005150R0JE73 which is a 150 ohm exactly matches what’s on the inside.  You could go as high a 1K with some phones or IEMs.
 
As for hum on one channel only:
 
Since the internal layout is not perfectly symmetrical, the noise floor is going to be louder on one side over the other.  This is true of most audio gear, once you magnify the noise floor.  Even if both sides were exactly the same layout, differences in tubes would be heard, so the real issue is hearing the noise floor at all.  With 1700 Miliwatts of output, anyone hearing hum has more than enough volume left on the dial to hurt themselves.  That means that for headphones that you hear hum with, there is too much gain or power.  Reducing it will give you more usable range on the volume control and reduce the hum by an equal amount.
 
 
 
Hope this helps!
 
Steve Deckert

 
Hey Steve,
 
Thank you for the answer. Considering I am having 4 pin outputs, could I make one with the default gain that it now has and the other with lower gain? Does this mean just adding a > 150 ohm resistor?
 
If the answer is positive, could it easily be applied just on one(4pin xlr or single ended) output? (What would be the resistor you would chose for this?) Will this influence the output impedance?
 
Thank you,
 
Dan

 

[thegrobe]

Since this is coming up again, I'll reiterate my experience. Maybe since Steve is following and has responded, perhaps he can comment on my experience/findings. Hopefully this can help find a solution? 
 
----------------------------------
 
This first part is old news, same experience many are having. Just a recap. 
 
- Taboo mk3, a low level background hum (both channels). Seems to be 60 Hz. Audible with LCD-3 when music is stopped, or quiet passages. I had mentioned before on this thread that it was inaudible with the HD800. I was mistaken. There was some background noise in the house, etc while I was checking it out. A later, quiet listening session I hear it, and it is similar as the LCD's, just maybe a bit less noticeable.
 
- I'm also concerned on how this affects the accuracy/transparency of the chain, if the whole time the headphone is recreating this humming in the background. 
 
- The hum is the SAME volume regardless of volume knob position. Regardless of the Taboo being used alone or with pre. The same with nothing at all connected to it. The same with the input tube removed.
 
- Gets louder and intrusive with either headphone with new lucid engaged. Therefore I don't use it much. I can live without it. I wish it was silent in standard mode though. 
 
- Level of hum is the same off speaker taps or 4 pin XLR out.
 
- My Taboo was returned to Decware to check out the hum, they didn't hear anything, everything checked out. They sent it back. Steve was very helpful though, called personally to discuss it. It was still an expense. Not as much as $$ the users in other parts of the world. But still not cheap. 
 
- I tried a DC blocking power conditioner. Didn't help. I was thinking maybe my power was dirty, and Decware's is clean, hence me hearing it and they don't. I have had no problems with any other gear, amps, anything. All quiet. Tubes, interconnects etc everything has been changed/checked. 
 
- My CSP3 pre is FANTASTIC. I have no noise, hum, anything with it. Super quiet. If you crank up the volume to 100% with no music playing, there is a VERY faint hiss detectable. But if you listened at those volumes your ears would melt and this whole hum problem would be the least of your worries. Nothing to complain about. 
 
- I realize the Taboo is a speaker amp at heart, and designed for the LCD, not designed for IEM/CIEM use. Let me say this though...My CIEM's sound FANTASTIC out of this amp, apart from the background hum, which is very intrusive. Other high powered desktop amps I've tried are silent in the background with IEM's. It would be nice to find a solution to this, so that all headphones can be used noise-free with this amp. 
 
------------------------------------
 
Here's where it gets interesting:
 
- The CSP3 is powered on, sitting near the Taboo. The Taboo has no power cord connected, no interconnects. No tubes installed even. Nothing. Just sitting there. IT HUMS. I can connect headphones to the Taboo and hear that damn humming. This is the same noise I hear constantly in the background from the Taboo. If I move the Taboo away from the CSP, it fades and goes away. BTW, the CSP powered off and the Taboo on, I get the noise. Of course. 
 
Here's my theory: The transformer is making a low level hum, oscillation, whatever you want to call it. (I'm no engineer or amp designer, please don't laugh at me Steve) The output transformers on the Taboo pick that up somehow, transduce it and send it on out the headphone cable. It stands to reason that if the Taboo picks up the noise "over the air" from the CSP being next to it, it would surely also pick up the same noise from it's own transformer. (??)
 
Would removing the transformer from the Taboo and having it in a separate base, say a foot and a half away, maybe cure this? Far enough that the transformer isn't causing whatever it's broadcasting on the internals of the Taboo. Maybe? Sounds crazy but I'm this close to gutting my Taboo, removing the transformer to a separate enclosure a bit farther away to try it. Warranty be damned. I'm pretty handy so I know it will survive. Might look crazy though. But might just add to it's charm. 

 

[Pentode Guy]

[quote
[/quote]
Dan, if your unit is less than 30 days old, Steve will pay shipping both ways.

 

[dan.gheorghe]

[quote

Dan, if your unit is less than 30 days old, Steve will pay shipping both ways.[/quote]

I am not that lucky ) . It would cost me over 450 EUR, I think.

 

[WNBC]

Out of curiosity which tubes are you HD800 users with your CSP/Taboo combo?    

 

[longbowbbs]

I had Mullard EL84's with a Genalex Gold Lion 6922 and a USAF-596 for the Taboo. The CSP2+ had the stock 6N1P and a pair of Genalex Gold Lion's with another USAF-596. Loved it.

 

[WNBC]

Thanks for insight.  USAF-596, one of these days......

  
 
 
Quote:

  I had Mullard EL84's with a Genalex Gold Lion 6922 and a USAF-596 for the Taboo. The CSP2+ had the stock 6N1P and a pair of Genalex Gold Lion's with another USAF-596. Loved it.