[Kendoji]

The hum on my Taboo seemed to settle down a bit last night after having the amp on for several hours.  It was still audible, but less prominent than when I first turned it on.  It's too early for sound impressions (which I'm rubbish at anyway), but so far it seems a bit less warm than my V200.  This means reaching for the HE-500 a bit more often than the HD 800 at the moment, which I suppose isn't too strange as the amp was specifically designed for orthos.
 
It's such a magnificent machine.  I love the quirky boutique hand-made look and feel of it.  The fact that there are absolutely no instructions in the box.  That none of the switches or plugs are labelled.  That the volume knob is perilously close to the scorching hot input tube.  

 

[Kendoji]

Oh and the bizarre new lucid mode.  It's such a wonderfully strange feature to include with the amp.  I can't imagine ever using it for a serious listening session, but it will be great to flick the switch when guests are over just to see the look on their face.

 

[longbowbbs]

Quote:

Quote:

Lol longbow. I know no one here will tell me it's a stupid idea. I have to do this, it's my decision making process.
I tried this- absolutely zero hum when unplugged and still playing. A dead black background. So that's good. I guess this unit is very sensitive to power issues. I wonder though could it be a noisy or faulty transformer...

I guess I'll get some sort of AC filter etc and keep experimenting.

I tried this, the hum disappeared right away when unplugged, but I don't think it's a power issue, because I tried my Taboo in 3 different locations, and bought a power regulator too, didn't do any good, the problem is in the machine.

I wonder if it is a tube? Mine Taboo is dead quiet.

 

[Kendoji]

It seems like a common challenge.  Has anyone put the question to Decware?

 

[Gustav Mahler]

A number of people have reported a similar problem with the Schiit Mjolnir (which I own).  In those cases dimmer switches seem to be the source of the problem.
 
Cheers!
 
Gus
 

 

[mmlogic]

Quote:

I wonder if it is a tube? Mine Taboo is dead quiet.

I've tried many tubes, 5R4 6BQ5 and 6299, I'm sure it's not a tube problem, tube hum change with volume, this hum is fixed.

 

[mmlogic]

Quote:

The hum on my Taboo seemed to settle down a bit last night after having the amp on for several hours.  It was still audible, but less prominent than when I first turned it on.  It's too early for sound impressions (which I'm rubbish at anyway), but so far it seems a bit less warm than my V200.  This means reaching for the HE-500 a bit more often than the HD 800 at the moment, which I suppose isn't too strange as the amp was specifically designed for orthos.
 
It's such a magnificent machine.  I love the quirky boutique hand-made look and feel of it.  The fact that there are absolutely no instructions in the box.  That none of the switches or plugs are labelled.  That the volume knob is perilously close to the scorching hot input tube.  

If you feel your Taboo sound too leaner, try Amperex 6299 (mine is white label PQ big O getter), that works for me, I've also tried Siemens cca and TFK ECC88, but they only make things worse. 

 

[negura]

For a fuller body sound I would get EL84s. Amperex 1960s do nice and I am actually preferring some Bentley EL84s I bought quite cheap in the UK (not exactly sure who makes them as they may actually be relabeled tubes).

 

[thegrobe]

Maybe the difference reported in hum/noise floor has to do with impedance of different headphones.

Example my LCD-3 are 45 ohm. Maybe using high impedance headphone such as HD800 @ 300 ohm it's not audible. Which may be weird because this amp was designed for LCD.

That's one other thing I've noticed, my other desktop amps I could use my CIEM's if I wanted. On this amp it's just a mess, unusable due to the hum. That's the acid test..anybody actually able to use IEM's with this?

This is a frustrating thing to deal with. If it's normal, it's barely acceptable. If it's power quality from my home, I need to troubleshoot it and spend $ on that (I've never had issues with ANY other gear - and the amp is already on a strip with A.C. filter/noise rejection) If the amp is actually faulty I need to identify that and ship it back and who knows what that entails ($) because I bought it used.

I guess I should ask Decware about it, but they have so far been non-responsive to my questions about purchasing a new CSP3 so not too excited about trying to get support for a second-hand amp.

I absolutely love LOVE LOVE the sound of this amp. But gotta figure out what's going on before I jump into buying the pre-amp.

Can anyone else hear a physical hum from the transformer? Nothing plugged in or out, the actual transformer humming a bit. Audible from maybe a couple feet away in a quiet room.

 

[OPR8R]

The weird thing about the hum is sometimes I hear it, sometimes I don't. Sometimes I'll hear a hum just before I start my listening session, but it's gone by the time I finish. Other times, it's the other way around. Sometimes I get a hum after listening to vinyl for an hour or so. Sometimes it's dead quiet. I'm not willing, at this point, to spend money trying to fix it, because while I listen to music I hear no hum. On the list of things that degrade my experience the hum doesn't even rank compared to my noisy neighborhood (cars, drunks, and wildlife), however, I'm hoping a move will kill both birds with a single stone. The thing is, I hate moving. I checked for a hum off the transformer and couldn't hear one.

 

[negura]

My Taboo is dead quiet. The only times I had hums was with one (clearly) bad tube and one vintage tube (1950s) before the pins went through a good doze of Deoxit and cleaning. I am no longer even getting that faint presence with the New Lucid Mode engaged. Don't ask me why, but I am very glad. Maybe it's the power regen.

 

[thegrobe]

My Taboo is dead quiet. The only times I had hums was with one (clearly) bad tube and one vintage tube (1950s) before the pins went through a good doze of Deoxit and cleaning. I am no longer even getting that faint presence with the New Lucid Mode engaged. Don't ask me why, but I am very glad. Maybe it's the power regen.

I checked out that regenerator you posted the link to earlier, looks like it's a 240v only unit otherwise I would give it a try.

So would you say your taboo is quiet enough that you could use sensitive ciem's without background noise?

It's odd, I can put the LCD's or even ciem's on there and crank the volume 100% (without music playing of course) and not a hint of hiss. None.

But the background hum is constant and does not change with volume.

I have a theory... that the quality control/ build of the transformers is a bit spotty. Some are good, some are noisy.

I guess I'll try to get Mr. Deckert on the phone sometime this week and help me troubleshoot. Probably need to send it in. Well there goes any $ I saved by buying used. Crap.

 

[negura]

I have several IEMs but I cba to test right now, however I am extensively using the LCD-3s. Dead quiet. 
I am also amping Stax that require about 20% more volume for the same dB as dynamics. With both the Taboo maxed and PWD2 preamp maxed, 0 background noise.

 

[negura]

Ok folks I am on a mission: I need EL84s that are similar in transparency and signature to the stock 6p15p. It appears the EL84 have additional power and I need it.
The Amperex EL84 I have are warmer and the Bentley too bright. Need to strike the fine balance. Any suggestions?

 

[longbowbbs]

Quote:

Ok folks I am on a mission: I need EL84s that are similar in transparency and signature to the stock 6p15p. It appears the EL84 have additional power and I need it.
The Amperex EL84 I have are warmer and the Bentley too bright. Need to strike the fine balance. Any suggestions?

Raz, I have a pair of these and I really like them....
 
http://www.upscaleaudio.com/products/Philips-6BQ5-%7B47%7D-EL84.html