New, Cheap Dynalo...

[LarsMarkelson]

DC offset is measured at the output with the pot turned all the way down. With a DMM (digital multimeter) set to DC volts, you measure from L (tip) to ground (sleeve) and R (ring) to ground (sleeve). These should ideally be <1 millivolt (0.001 Vdc), but anything under 5-10mV should be fine. Easiest way to do it is to use a blank 1/4" phone plug and do your measurements across the contacts; avoids having to open the unit.

Excessive DC offset could trash your IEMs. I'm not pointing fingers at the manufacturer or anything, but since this is a DC coupled amp, there are no coupling caps to protect you from this.

One other thing you could try is unplug the amp from your source, turn the volume all the way down, and then listen. If you still hear the noise, then it is the amp. If not, blame your source.

Okay cool! I'm headed to the hardware store now to pick up a digital multimeter. I'm a total noob at electronics besides buying and using them. Is this what you meant by blank 1/4" phone plug, Neutrik 1/4 in Phone Plug, Solder Internal Strain Relief Metal | EP-6 (EP6) | Neutrik ?

I have a 1/4" male to 1/8" female adapter from RadioShack that is seemingly all metal, would I be fine using that? If not, hopefully the hardware store has the 1/4" plugs. Thanks for the help so far, really appreciate it.

Oh yeah, I unplugged amp from source with volume all the way down and I still heard the hiss. So it's definitely the amp.

[LarsMarkelson]

I'm pretty sure there's something wrong with your unit Lars, I'd get it checked. I just measured DC offset on mine and I get 2mV if you want to use that as a reference. Also, I only hear hiss at very high volumes, far outside my comfortable listening range and the only time I can hear a small hum is with the JH13, otherwise it's completely silent.

I talked to Maniac about the problem and he asked me if my gain was at 11x, the default, which it is. He made it out to seem like it was a problem with the gain and that changing the unit to unity or 3x would fix it. Are you at 11x too?

[Pars]

Okay cool! I'm headed to the hardware store now to pick up a digital multimeter. I'm a total noob at electronics besides buying and using them. Is this what you meant by blank 1/4" phone plug, Neutrik 1/4 in Phone Plug, Solder Internal Strain Relief Metal | EP-6 (EP6) | Neutrik ?

I have a 1/4" male to 1/8" female adapter from RadioShack that is seemingly all metal, would I be fine using that? If not, hopefully the hardware store has the 1/4" plugs. Thanks for the help so far, really appreciate it.

Oh yeah, I unplugged amp from source with volume all the way down and I still heard the hiss. So it's definitely the amp.

Since you have a 1/4" to 1/8" adapter, you could just grab a cheap 1/8" mini plug from radioshack, or a 1/4".

What maniac was stating about gain is perhaps true as IEMs require very little gain and having too much will appear as noise since they are so sensitive. If you use this amp with other less efficient phones, you will need to balance between the needs of those as well.

[GPH]

I talked to Maniac about the problem and he asked me if my gain was at 11x, the default, which it is. He made it out to seem like it was a problem with the gain and that changing the unit to unity or 3x would fix it. Are you at 11x too?

Yes, mine is 11x too and there's no hiss present except at very high volume levels.

[LarsMarkelson]

Alright I just did some measurements:

L (tip) to ground (sleeve) = 0.46

and R (ring) to ground (sleeve) = 0.86

Which is apparently very good... This is really really strange!

I guess the solution is to change the gain. Still don't know why GPH would have no hiss and I would. Actually, did you get the HA-006+ early in its release? I know Maniac changed one of the innards to, oddly enough, lower noise floor... which is indicated by a sticker on the back that says HA-006+ Plus Edition (this is what I have).

[Pars]

0.46 and 0.86 what? Volts? Millivolts? What meter did you use and is it autoranging, or did you have to select a range? If manual, what range was it on? 0.46 could be 460mV, which of course would not be too good.

[LarsMarkelson]

0.46 and 0.86 what? Volts? Millivolts? What meter did you use and is it autoranging, or did you have to select a range? If manual, what range was it on? 0.46 could be 460mV, which of course would not be too good.

With Fitz's help in chat (ty again Fitz), I set it to the 200m marking on the V= (bottom line is dotted) section.

[Pars]

Then that is fine

[K3cT]

Lars, I think the electrical wiring in your house could be a culprit too. I attend meets so sometimes my gears will pick up hiss when I set it up somewhere else.

[LarsMarkelson]

Ya I think that has to be it. That or a wizard...

Btw, I did confirm with GPH that he has the Plus Edition as well. So presumably the exact same amp... just my power is dirtier than his. When I get my JH-13 back from refit I may or may not test different outlets around the house for noise... depending on if I get my upgraded Dynalo (HA-006++ SE) with unity gain by then. Maniac said on the other forum that they'd be shipping out on Thursday.

[LarsMarkelson]

Ya I think that has to be it. That or a wizard...

Btw, I did confirm with GPH that he has the Plus Edition as well. So presumably the exact same amp... just my power is dirtier than his. When I get my JH-13 back from refit I may or may not test different outlets around the house for noise... depending on if I get my upgraded Dynalo (HA-006++ SE) with unity gain by then. Maniac said on the other forum that they'd be shipping out on Thursday.

Small update, none of the outlets in the house gave me a clean feed, which is not surprising considering the old age of the house. I've decided against trying to change the gain myself since I have 0 soldering experience and don't want to risk bricking my amp. I've got the HA-006++ SE coming my way soon though, Maniac just posted pics of it on the other forum... I'll copy and paste his post exactly to here.

[LarsMarkelson]

First pics of HA-006+ completely upgraded Dynalo HA-006++ SE

Originally Posted by Maniac on other forum

First production units! We are testing them to make sure that there are nothing that we missed when we are translating the prototype to production. Enjoy!

Note that the transformer is now plugs in with two new boards at the back of the unit. This is not just throwing a few upgrade parts on a already good amp, but pretty much a total upgrade of the original.

The board that costs us quite a bit of time to have it done properly.

The new RCA sockets, it solidly constructed and it performed well (I believe it is also used on other fairly expensive audio equipments, but I can't recall the exact brand at the moment).

Enjoy, will keep everyone updated as soon as we have more.

Thoughts anyone? Looks purty to me, pretty excited to get it. It also has a 22 step attenuator for volume control instead of pot on the original.

[GPH]

Those cables must cut bass like crazy, according to the 18AWG rule of thumb.

[K3cT]

Someone more experienced or Maniac can correct me if I'm wrong but wouldn't an unshielded transformer like that induce noise to the circuit due to the close proximity?

[LarsMarkelson]

Someone more experienced or Maniac can correct me if I'm wrong but wouldn't an unshielded transformer like that induce noise to the circuit due to the close proximity?

Cool, I asked Maniac about it on email, this is what he replied:

The toroidal transformer leaks very little magnetic field, and what it

does leak is very easily controlled. Unlike an EI transformer, which

leaks like a broken dam, toroidal transformer often causes less

interference than even shielded EI transformer.

As for the tiny wires in the photo, they are there to make sure both

unit got the same music while burning in, listening test are done with

that golden RCA cable.

[spritzer]

The RCA sockets are Vampire and used by pretty much everyone as they are one of the few good PC mounts you can buy.

[Pars]

I hope that was tongue in cheek by GPH...

[GPH]

I read it in a treaty on electronics written by a certain R. Samuels.

Please if you make an adaptor your self make sure you use a good quality wire with 18 AWG. Using thinner wire might not give you all the bottom end that the amp is capable of.

Edited May 13, 2010 by GPH

[Pars]

Ah yes... good stuff.

[Shahrose]

I just got the HA-006++ upgraded version ($450).

Initial impressions: Build quality is pretty good, and the pot has annoyingly large steps, even at gain 3 (guess I should have gone for gain 1). I'll do a mini sound comparison with the M^3/Sig-11 in my setup after about 100 hours of pink-noise burn-in.

[LarsMarkelson]

I just got the HA-006++ upgraded version ($450).

Initial impressions: Build quality is pretty good, and the pot has annoyingly large steps, even at gain 3 (guess I should have gone for gain 1). I'll do a mini sound comparison with the M^3/Sig-11 in my setup after about 100 hours of pink-noise burn-in.

I too got the HA-006++ a couple days ago, haven't been listening a ton yet though. You're mainly using it with the HD-800? I'm using HF-2 and JH-13 and I got 1x gain. It's pretty crazy even with 1x I am only using the first 3-4 steps ever. Looking into getting some kind of attenuation because of that, right now it's between an inline attenuator (Goldenjacks) or a passive volume control (SM Pro Audio Nano Patch+)... still researching to figure which degrades the signal the least.

I also might need a power conditioner because even with 1x gain I can hear a distinct buzz on the first two steps with my JH-13 (goes away pretty much at 3 though). I attribute this to the over 100 year old electrical system I'm using, not the amp.

I never realized how important proper gain setting is... my previous amp HA-006+ was set at default 11x gain and I compensated this by lowering computer volume to 6%. Now I'm back at 100% with new amp and even at very low level listening I'm hearing all this new detail that I never heard before.

Oh also Shahrose if you know how to solder or you know someone who can help you, talk to David and he will send you instructions on how to change your gain to 1x.

[Dusty Chalk]

I never realized how important proper gain setting is... my previous amp HA-006+ was set at default 11x gain and I compensated this by lowering computer volume to 6%. Now I'm back at 100% with new amp and even at very low level listening I'm hearing all this new detail that I never heard before.

It's not just gain -- the main problem here is that you had the computer at 6% -- 100, 50, 25 are the three best choices, in order, anything else pretty much sucks, because it's not just a bit truncation (and that's assuming you can get it at exactly those values -- really should try to get it at 100%, that's the only one you can be sure of).

[Shahrose]

Thanks Lars, I actually received an email from David an hour ago asking if I wanted the gain-reduction instructions...I'll pass them off to a friend who'll do it for me. A gain of 1 is more than enough I think. At the moment, I can't even go above ~9 o' clock (4 steps) because it's far too loud with the HD800/HD650 and even more so with the PX100/KSC-75.

BTW, I don't hear any sort of noise from the amp, even at the highest step.

Oh and I've also found that reducing the volume on the computer (digitally) reduces SQ. I always have the output set to bit-perfect so the signal remains at 100% volume and completely intact without truncation.

[LarsMarkelson]

Here's a pic I took of the internals of the HA-006++ SE

99% sure I'm going to buy a passive volume attenuator, specifically the SM Pro Audio Nano Patch+

Only thing is it takes TRS (balanced and unbalanced) and I'm all RCA. The only thing I can find is RCA -> TS adapters (and vice versa), anyone know if those will work (TS going into TRS)?

Edited June 6, 2010 by LarsMarkelson

[Shahrose]

After a bit of listening here are my thoughts on the HA-006++ (the new upgraded one):

-It's smoother and slightly warmer than the M^3 (AD8610) and Gilmore Lite (the Glite is the thinnest/brightest of the 3 amps as far as I can recall)

-It is not a fast-sounding amp. The transient speed (most noticeably in the bass) isn't as good as the M^3. Basically the M^3 has more control.

-Its dynamic range is not as good as the M^3. The M^3 also has a blacker background between notes, as well as a slightly more airy presentation than the HA-006++

-The soundstage is larger than the M^3, but also a bit more diffuse. Both amps have great layering within the soundstage. The HA-006++ just produces "larger" aural images, as if it's playing in a larger space.

Conclusion: I find the HA-006++ to have a more pleasing tone, a larger soundstage, more bass and less treble than the M^3. OTOH, it also has less dynamics, slower transients, less top-end air/microdetail and more diffused imaging than the M^3.

The HD800 certainly benefits from the slightly tubey (and forgiving) sound of the HA-006++ at times, but the M^3 is the technically superior (and more transparent) amp IMO.