Solid-state amp design

[seacard]

I have no engineering or design background, so these may be stupid questions, but that's never stopped me before.

Can you tell what an amp will sound like from the amp's design? Often times, somebody says that "Amp X is poorly designed" -- does that correlate to sound? Kevin Gilmore, whose opinion and judgment I value and trust probably more than any other designer in this field, may be able to answer this question best. Sometimes you see him saying that something is a poor design, or a very simplistic design, etc. Can you assume that such an amp will not sound as good as a well-designed one? I have a feeling the answer is no, but if it is yes, what are the best-designed solid-state amps?

[Bidoux]

My 0.2c. I think that a well designed amp according to KG doesn't bring any color or sound signature (Gs-X, GS-1 and Gilmore lite are all based on Dynalo, they all sound quit neutral). A capacitor coupled amp will have a capacitor sound, it seems that it is bad to kevin.

For instance, RSA HR-2 and graham slee solo are both capacitor coupled, they are "bad design" and have a "warm sound signature".

What I said is only my personnal opinion. I'm sure Kevin Gilmore will tell what he thinks here.

[swt61]

I think you can get a general idea of what an amp is going to sound like from the design. There are a lot of factors at work however that come into play.

For instance all Beta22 solid state amps don't sound exactly the same. Parts selections and layout factor into the final sound signature.

Others can impart much more knowledge here than I however.

[digger945]

^Agreed.

I have not listened to every amp on the planet yet, but I would have to say in my very limited experience that the KG designed Dynahi/Dynamite that I have now would indeed be, to me and in my own words, neutral. It doesn't wow you with anything at all, it's just.....well.....right, to my own ears. It would best be described by me as accuracy with great control. It also has the most awesome bass slam I've ever heard in a HP amp, but again, I haven't heard them all so.....

The man knows a thing or two about his creations. I look forward to the next KG amp in the works now.

[kevin gilmore]

My 0.2c. I think that a well designed amp according to KG doesn't bring any color or sound signature (Gs-X, GS-1 and Gilmore lite are all based on Dynalo, they all sound quit neutral). A capacitor coupled amp will have a capacitor sound, it seems that it is bad to kevin.

For instance, RSA HR-2 and graham slee solo are both capacitor coupled, they are "bad design" and have a "warm sound signature".

What I said is only my personnal opinion. I'm sure Kevin Gilmore will tell what he thinks here.

Nope you were not paying attention. Ray's hr2 is a dual power supply dc coupled unit.

no caps in the signal path. graham slee is same exact circuit with only one power supply

and input and output caps. Lots of open loop gain and what amounts to a class B

output buffer.

[Icarium]

They are chip amps though yeah? The HR-2 and the Graham amp?

[recstar24]

They are chip amps though yeah? The HR-2 and the Graham amp?

yes or I believe the technical term are buffered opamps as the opamp feeds a pair of transistors for output (at least with the HR2). The eddie current ECSS is in a similar branch of buffered opamp designs.

[Dusty Chalk]

Can you tell what an amp will sound like from the amp's design?

I can't.

[Fitz]

I can't.

Try looking at the chassis work instead, you can get a better idea if an amp will sound good that way. The one with moar blinkenlichten, switches, and meters is probably the better one.

[feckn_eejit]

I can't say I'm technically knowledgeable enough to tell whether something will sound great or not based on its design, but I have found going by weight pretty reliable actually! Figure it usually means moar beefy powar suppliez......

[seacard]

I can't.

See, this is why you are banished here. At many other headphone forums, people can tell what an amp sounds like just by reading other people's descriptions of it, without ever seeing or hearing it.

[Bidoux]

Nope you were not paying attention. Ray's hr2 is a dual power supply dc coupled unit.

no caps in the signal path. graham slee is same exact circuit with only one power supply

and input and output caps. Lots of open loop gain and what amounts to a class B

output buffer.

Do you mean those amp are class B ? How can you tell they are class B (curious to learn)

BTW sorry for the lack of attention.

[swt61]

How can you tell they are class B (curious to learn)

BTW sorry for the lack of attention.

Uhm, That's kind of like asking Versace "How do you know that's a shirt". But...

...

anyway!

Edited July 28, 2009 by swt61

[Bidoux]

I know generally push-pull are classe B (or AB) but kevin's Gilmore Dynalo has the same output stage and it is class A (pure class A ).

[n_maher]

Try reading this.

Amplifier classes of operation

[darkless]

Since we're talking about designs and sound, will a dynamid driving eg. a pair of HD6x0 or HD800 at 65-70 dB (my normal listening level) sound any different compared to a dynamight?

What about lower-impedance cans such as the L3000?

I'm assuming both designs are well-implemented using decent components of similar quality and no "tweaks" applied, e.g. to boost bass.

To put it another way: If I never listen at rock concert levels and don't have any hard-to-drive phones like K340/K1000/whatever, would I be able to tell any difference between the dynamid and dynamight?

I'm already aware that Dreadhead hasn't been able to hear any difference between his GS-X and balanced Beta 22 at similar volume levels (67 dB). I don't know if he's ever had the chance to compare either amp to a dynamight, however.

[Bidoux]

Dynamid is a balanced Dynalo (it is also GS-X). The dynamight is a balanced dynahi (it is not available commercialy). Since the Dynalo and dynahi share the same overall design, the dynahi was made after the dynalo and is supposed to be better.

i'm not sure it is a good thread to ask, we are talking about SS design here.

[ecclesand]

I use the sniff test. Usually the best sounding amps smell the worst. That's been my experience.

[cetoole]

Do you mean those amp are class B ? How can you tell they are class B (curious to learn)

BTW sorry for the lack of attention.

Only one diode drop biasing the emitter-follower.

[darkless]

Dynamid is a balanced Dynalo (it is also GS-X). The dynamight is a balanced dynahi (it is not available commercialy). Since the Dynalo and dynahi share the same overall design, the dynahi was made after the dynalo and is supposed to be better.

i'm not sure it is a good thread to ask, we are talking about SS design here.

Thanks, but I didn't ask which amp was supposed to be better. My question was:

will a dynamid driving eg. a pair of HD6x0 or HD800 at 65-70 dB (my normal listening level) sound any different compared to a dynamight?

Thus, my question still stands unanswered.

I think my question is relevant in the context of the thread topic, given that I'm asking if there's any difference in sound between the two SS designs mentioned above when ruling out the need to power hungry phones, small speakers or amping to ear-bleeding levels.

However, if my question is totally OT, I apologize and humbly ask for a mod to kick this stuff into its own thread.

[digger945]

Your question will be answered when you are listening to a gsx and dynamite side by side within your own setup.

They are similar amps, but not the same parts:p. After all, only a handful of people have ever built the Dynamite:o

DIY RESOURCES - Kevin Gilmore DYNAMIC HEADPHONE AMPLIFIERS and POWER SUPPLIES

HeadWize - Project: A Pure Class A Dynamic Headphone Amplifier by Kevin Gilmore

I've never seen a bridged pcb for either hi or lo.

[darkless]

Thanks, I had already checked out the resources you linked. They contain a lot of great information.

Sadly, listening side by side in my own setup will never happen. To my knowledge no one in Denmark has ever built a dynamight. I was hoping that someone from the US had had a chance to compare the two designs against each other and would chime in with their impressions regarding the two sound signatures.

What I don't understand, however, is that a lot of people are quick to claim the higher output amp to be the better sounding option when in reality there have been no such comparisons?

For the usage pattern that I detailed in my previous posts, which I'd think would apply to most head-fiers, there would be little to no incentive to go with the more powerful dynamight or balanced Beta 22 assuming the dynamid (or GS-X) has enough power surplus to handle regular phones at normal listening volumes. In this case, preference would then have to be based on sound signature, but with no such comparisons available it's hard to pick a winner.

[grawk]

I think several people on here have heard both, give them some time to chime in, and don't let the newbie distract you

[Icarium]

Yeah I've heard both dynalo(s) and a dynahi side by side. Right now I only have a gilmore balanced reference and a dynahi currently so I haven't compared balanced to balanced... but up until recently I had a gilmore lite and a gilmore v2 as well.

My dynahi has a sigma22 for a power supply and the gilmore lite is a version 2 gilmore lite with no dps. The gilmore v2 is somewhere in between a gilmore lite and a gs-1... The gilmore balanced reference has a nicer power supply than the GS-X I think.

With ad2k/qualias/w5k the dynahi stomps all over the gilmore lite and the gilmore v2. The balanced reference however holds its own.

Compared to the lite the dynahi had a much wider soundstage. You'd hear exactly where the soundstage ends with the lite while there seemingly were no limits to the dynahi. If a sound is placed really damn far away, then it would show up there. With the lite it seemed like there was a defined point on the left and right side where sounds will not show up further no matter the recording. The dynahi also had much better mids, was more impactful and had way better bass.

The v2 was about the same as the lite, but had much improved bass and better mids.

The gilmore balanced reference has the same sort of "infinite" soundstaging like the dynahi, but is more laid back. It isn't as punchy as the dynahi.. Everything else is about on par. The dynahi mighttt still have the slight edge on bass and mids, but really it's less certain. It's a toss up which I like better. Need my dynamight and my balanced dynafet asap.

Overall the dynahi seemsss a little bit faster but that might just be the punchiness.

[jcx]

Since we're talking about designs and sound, will a dynamid driving eg. a pair of HD6x0 or HD800 at 65-70 dB (my normal listening level) sound any different compared to a dynamight?

What about lower-impedance cans such as the L3000?

I'm assuming both designs are well-implemented using decent components of similar quality and no "tweaks" applied, e.g. to boost bass.

To put it another way: If I never listen at rock concert levels and don't have any hard-to-drive phones like K340/K1000/whatever, would I be able to tell any difference between the dynamid and dynamight?

I'm already aware that Dreadhead hasn't been able to hear any difference between his GS-X and balanced Beta 22 at similar volume levels (67 dB). I don't know if he's ever had the chance to compare either amp to a dynamight, however.

very dynamic music peaks may be ~25 dB above average levels, 95 dB pk spl from the senns would require < 1 mWrms

if this is truly your listening scenario then you really don't need an amp - at worst just modify your source line out stage with a ccs load of ~4mA and any reasonable quality audio op amp will happily drive your cans with inaudible distortion in Class A

I wouldn't expect anyone to be able to make fine distinctions at such low average listening levels - certainly little recorded music would "sound live" simply due to the Fletcher-Munson loudness effect changing the perceived frequency balance

You do need to keep the level far below most live presentations for extended ”background music” listening of hours a day but I want an amp to drive my cans to near live levels if only for a