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The Decware TABOO MK 111 Appreciation Thread - Page 115

post #1711 of 1867

I liked the CSP/Taboo combo very much. The Taboo by itself and the CSP by itself are both excellent as well. I actually prefer the CSP with the HD800 rather than the Taboo if they are set up individually. The Combination gives more weight and power behind the signal. It would be interesting to listen to the combo vs say a Stratus or EC and see how they compare.

post #1712 of 1867
I have received two emails from Steve regarding problems with their internet provider. I will copy and paste his remarks to address the issue.

Hi Don,

I appreciate your e-mail. We have had nothing but trouble with our e-mails and internet all summer. Much of it out of our control. We don't ignore anyone on purpose of course, but sadly our business is located in a rural area and we have to get our internet and phone through the cable, which goes out constantly. There are no other high speed providers in our area. It doesn't seem normal to have the phone go out every time the internet goes out, but that's the reality and I'm sure it leads people who try to contact us to conclude that we "just don't care". It's so frustrating.

Please feel free to quote this if you post on head-fi. Right now I'm desperately trying to update over 400 suppliers with our new e-mail address.

The following link can also be posted on headfi: http://www.decware.com/newsite/contacts.html
It has our new contact e-mails listed.


- Steve Deckert

Decware / High Fidelity Engineering Co.
75 S. Riverview Dr. East Peoria IL 61611
Website: www.decware.com
Blog: zenamps.wordpress.com
Phone: (309) 822 5255

This December all decware e-mails stopped working properly and as of Dec 12 were blocked entirely for reasons yet to be discovered. If you have had problems contacting us, this was likely the reason.

Sending any e-mails to decware.com results in a bounced e-mail and we of course never receive it.

We have updated our contact information on the web site with new e-mails.

Please update your records, and sorry for the inconvenience.



I don't blame any potential buyers for being unhappy when emails are not returned, but perhaps a phone call is in order before giving up on Decware. After all, you might have invested a chunk of money into one of their amps : )

I hope Steve gets this fixed and can focus on building great amps again!

Don
post #1713 of 1867

Hey guys,

 

I have been reading the thread a little and I have seen that there are a lot of users that experienced a hum with taboo.

 

I would appreciate it if everybody who didn't solve this issue would write their experience with the hum and how it acts. ( for the ones that have it only on one channel as I do, did you find it affects the sound on that channel even if by a small amount? )

 

Thanks,


Dan


Edited by dan.gheorghe - 12/24/13 at 5:39pm
post #1714 of 1867

Dan, hum is a mystery to a lot of us.  When we eliminate the influence of music source, tubes, and power source then that's a dead end as most of us are not able to work on these amps or we send it into Decware.  For example, I have a CSP3.  There is no hum unless I have the volume pot pinned to the left.  When it is pinned to the left there is an extremely loud hum whether using low or high impedance headphones of varying efficiencies.  Some contact is being made because when you turn the knob all the way left there is something metallic that forces it to stop moving.  When the volume knob is pinned to the left there is no hum.  Weird right?  Something I'm doing?  I can't figure it out.  In the end there is a hum from 6-7 o'clock on the dial.  From 7-5:59 o'clock there is no hum.  I should probably send it into Decware but the amp sounds fantastic.  What would you guys do?           

post #1715 of 1867
Quote:
Originally Posted by WNBC View Post
 

Dan, hum is a mystery to a lot of us.  When we eliminate the influence of music source, tubes, and power source then that's a dead end as most of us are not able to work on these amps or we send it into Decware.  For example, I have a CSP3.  There is no hum unless I have the volume pot pinned to the left.  When it is pinned to the left there is an extremely loud hum whether using low or high impedance headphones of varying efficiencies.  Some contact is being made because when you turn the knob all the way left there is something metallic that forces it to stop moving.  When the volume knob is pinned to the left there is no hum.  Weird right?  Something I'm doing?  I can't figure it out.  In the end there is a hum from 6-7 o'clock on the dial.  From 7-5:59 o'clock there is no hum.  I should probably send it into Decware but the amp sounds fantastic.  What would you guys do?           

 

I feel like the hum from the left channel affects the transparency compared to the right one even if by a very subtle margin (or maybe I am crazy...) . Imagine that the membrane has to move continuously to reproduce the hum. That may affect the reproduction of the other sounds. For me it's kind of complicated, considered I would have to pay ~700$ for the shipping to USA and backwards. There would also be the risk of them sending it back with the same problem as I have read here. In January I will try putting >150 ohms resistors on the headphone outputs as Steve suggested (he suggested 300) . I have a service guy which already tried getting it to 170 gradually from 150, but with no results. (not sure why he didn't try a big one from start to see if it works first ) 


Edited by dan.gheorghe - 12/25/13 at 2:25pm
post #1716 of 1867

Would these resistors be easily swappable?  I wonder what the effect on sound will be with your low impedance LCD-X and high impedance HD800.  Keep us informed.   

 

 

 

Quote:

Originally Posted by dan.gheorghe View Post

 

I feel like the hum from the left channel affects the transparency compared to the right one even if by a very subtle margin (or maybe I am crazy...) . Imagine that the membrane has to move continuously to reproduce the hum. That may affect the reproduction of the other sounds. For me it's kind of complicated, considered I would have to pay ~700$ for the shipping to USA and backwards. There would also be the risk of them sending it back with the same problem as I have read here. In January I will try putting >150 ohms resistors on the headphone outputs as Steve suggested (he suggested 300) . I have a service guy which already tried getting it to 170 gradually from 150, but with no results. (not sure why he didn't try a big one from start to see if it works first ) 

post #1717 of 1867
Quote:
Originally Posted by WNBC View Post
 

 

If you know what you are doing, I think it could be easy. From what Steve said, a 300 ohm impedance on the output instead of 150 would reduce the power with ~10%. That would mean that you will have to get the volume knob on higher grounds. Will tell you the results in January. I sure hope it fixes the hum.

 

I think both lucid modes rise the gain and with lucid mode 1 the hum becomes stronger and even stronger with lucid mode 2.

 

So, I think reducing the gain will make the hum inaudible.


Edited by dan.gheorghe - 12/25/13 at 4:09pm
post #1718 of 1867
Quote:
Originally Posted by dan.gheorghe View Post
 

 

I feel like the hum from the left channel affects the transparency compared to the right one even if by a very subtle margin (or maybe I am crazy...) . Imagine that the membrane has to move continuously to reproduce the hum. That may affect the reproduction of the other sounds. For me it's kind of complicated, considered I would have to pay ~700$ for the shipping to USA and backwards. There would also be the risk of them sending it back with the same problem as I have read here. In January I will try putting >150 ohms resistors on the headphone outputs as Steve suggested (he suggested 300) . I have a service guy which already tried getting it to 170 gradually from 150, but with no results. (not sure why he didn't try a big one from start to see if it works first ) 

No, you're not crazy, even the slightest hum can veil the sound, that's why I feel my Taboo 3 lack transparency though it has top image and separation, and I'm suffering from the same situation you're in, can't risk to send it back from the other side of the earth and got it back with the same problem.  

post #1719 of 1867
Quote:
Originally Posted by mmlogic View Post
 

No, you're not crazy, even the slightest hum can veil the sound, that's why I feel my Taboo 3 lack transparency though it has top image and separation, and I'm suffering from the same situation you're in, can't risk to send it back from the other side of the earth and got it back with the same problem.  

Damn man...this is exactly my situation... so I feel you...I so feel you.... :)) I am not alone any more :))

 

I am going to wait to see if there is a solution to this problem, but If there isn't this will go as a huge con/minus in my review on taboo. It really annoys me, as I feel that it is capable of excellent transparency...


Edited by dan.gheorghe - 12/26/13 at 10:24am
post #1720 of 1867
Haha yep same here. I still hope Steve comes up with a solution for these issues. But for now, while I still lllike the Taboo with headphones I'm increasingly starting to think of it as a speaker amplifier primarily.
post #1721 of 1867
^ this is certainly troubling. I live in New Zealand but was fortunate to receive two problem-free Decware amps. One of them, curiously, was previously owned by a head-fier in Switzerland who had hum and noise problems he couldn't eradicate. It (a CSP2) was checked out by Decware and I believe found problem-free before its journey to me. It is, I admit, picky about tubes but otherwise superb.

I used to be in software-development and there's nothing worse than trying to debug a system if one can't recreate the conditions the client is experiencing. I wonder if that's the problem here? Maybe some of these amps - especially because of their purist, simple design - are somewhat sensitive and...well...the controlled conditions of a test-bench won't necessarily identify the problems and hence lead the designer to their fixes.

Another thought is I have a (highly uninformed!) suspicion these amps are sometimes sensitive to EMI. Someone in another thread commented recently (don't remember where, but I don't follow many threads - maybe the LCD3 or LCDX or Gary's mega DAC-shootout thread) about how some (or a particular?) dac generated EMI easily picked up by some amps. There was some talk about this earlier in this thread too I think...

I know some of the Schiit gear was vulnerable to mains-carried interference from light dimmers...

Steve monitors this thread from time to time, and will certainly have some much more informed comment to make if he sees this! Btw Dan, have you been in touch with Decware about this?
post #1722 of 1867
Quote:
Originally Posted by AiDee View Post

^ this is certainly troubling. I live in New Zealand but was fortunate to receive two problem-free Decware amps. One of them, curiously, was previously owned by a head-fier in Switzerland who had hum and noise problems he couldn't eradicate. It (a CSP2) was checked out by Decware and I believe found problem-free before its journey to me. It is, I admit, picky about tubes but otherwise superb.

I used to be in software-development and there's nothing worse than trying to debug a system if one can't recreate the conditions the client is experiencing. I wonder if that's the problem here? Maybe some of these amps - especially because of their purist, simple design - are somewhat sensitive and...well...the controlled conditions of a test-bench won't necessarily identify the problems and hence lead the designer to their fixes.

Another thought is I have a (highly uninformed!) suspicion these amps are sometimes sensitive to EMI. Someone in another thread commented recently (don't remember where, but I don't follow many threads - maybe the LCD3 or LCDX or Gary's mega DAC-shootout thread) about how some (or a particular?) dac generated EMI easily picked up by some amps. There was some talk about this earlier in this thread too I think...

I know some of the Schiit gear was vulnerable to mains-carried interference from light dimmers...

Steve monitors this thread from time to time, and will certainly have some much more informed comment to make if he sees this! Btw Dan, have you been in touch with Decware about this?

 

From what I see here, Decware didn't test their amps with more headphones before releasing them into the market.

 

I have been in contact with Steve. One of his guess would be

Quote:
" My guess is a ground issue on one channel caused from excessive vibration during shipping"

 

If that is the case (but I don't think so as everything looked ok inside), that would suck...as on the way back from repairs...the same thing could happen again...

 

He also suggested changing the resistors on the outputs:

 

Quote:

Presently there are 150 ohm 6.5 watt resistors that can be increased to 300 ohm.   It's just enough to quiet things down a bit but shouldn't be an issue with the HD800.  You'll just have to have the volume control a click or two higher.

 

 

The service guy from jack-fi.ro only tried to increase the resistors gradually from 150 to 170 with no luck and then Christmas came and he had no time left... I am curious why he didn't try at first a bigger resistor to see at least if it works... and then go gradually to see what is the smallest added resistance that makes the hum go away. So I am going to wait until January for him to test again...

post #1723 of 1867
Steve suggested my hum issues were tube related, even though I had already excluded that possibility. Then I got a power regenerator, which didn't help. I'm a couple months I'm moving to a different apartment - am curious if that will somehow make a difference. Though again at this stage I'm basically happy with the amp, especially through speakers.
post #1724 of 1867

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.

 

 

 

               
  Transformer Hum and Static Noise from Taboo MKIII      
  Headphone Impedence Sensitivity Transformer Hum [?]  
  ohms dB/mW TRS XLR Static/Wooshing  
  Audeze LCD-X 22 96 Significant Significant Significant  
  Grado SR225i 32 98 Significant n/a Significant  
  Shure SE530 36 119 Loud n/a Loud  
  Alpha Dog 50 98 Some n/a Not apparent  
  AKG K702 62 105 Just barely n/a Not apparent  
  Darth Beyer 80 96 Some n/a Not apparent  
  Senn HD600 300 112 Just barely n/a Not apparent  
  Notes:            
  1 Amp was plugged in to circuit separate from all other audio equipment.  
  2 No inputs were connected to amp.        
  3 There was no discernable difference in noise levels with complete tube set change.  
  4 The noise was biased toward the left channel (60/40?, 70/30?), even with output tube swap.
  5 There was no apparent increase in noise when switching "Original Lucid Mode" on/off.  
  6 There was a significant increase in noise when engaging "New Lucid Mode."  
  7 The noise level did not change with respect to volume setting.    
  8 The noise level did not change when swapping output jacks or changing output jack selection.
  9 The static/wooshing noise fluctuated inconsistently.       
                 
  Noise level scale          
  Just barely:  Likely not noticeable if not listening for it      
  Some:  Noticeable with no music playing or during soft passages    
  Significant:  Evident during music        
  Loud:  Intolerable          
                 
post #1725 of 1867
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!)
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