Simple Killer Amp - Listening impressions

[jam]

Jacco,
...................there you go!

Jam

 

[lineup]

these days, this topic is more like:

Bring Back That Greggy Ball

An externally hosted image should be here but it was not working when we last tested it.

Released 8 November 1974, reached number 2, on chart for 42 weeks,
achieved Gold status
---------------

In 1974 The Queen released album 'Sheer Heart Attack'
'Killer Queen' was a big hit from this album.
But this song below was also included.
---------------

Bring Back That Leroy Brown
Track 11. Written by Freddie Mercury. Album version 2:16

Bring back, bring back
Bring back that Leroy Brown (yeah)
Bring back, bring back
Gotta bring that Leroy Brown (back)

Bet your bottom dollar bill you're a playboy (yeah, yeah)
Daddy cool with a ninety dollar smile (wow, wow, wow, wow, yeah)
Took my money out of gratitude
And he get right outta town (yeah)
I gotta getty up, steady up, shoot him down
Gotta hit that latitude (babe)

Bring back, bring back
Bring back that Leroy Brown (yeah)
Bring back, bring back
Gotta bring that Leroy Brown (back)

http://www.ultimatequeen.co.uk/

 

[ctviggen]

ShinObiwan:

Don't you also have an Aksa? If so, I'd be interested in a comparison of Greg's amp and the Aksa.

 

[ShinOBIWAN]

ShinObiwan:

Don't you also have an Aksa? If so, I'd be interested in a comparison of Greg's amp and the Aksa.

Yep, I've got an AKSA 55N+ that I'll be pitching against the SKA's. They're from very different philosophies, one is 'straight wire with gain' and the other 'intentionally very slightly coloured'. Should be interesting to see which I prefer, although I must say the 55N+ is a cracking amp anyway.

I don't have any heatsinks for the SKA's yet though - bought everything else expect those, which is just typical for me.

 

[ctviggen]

Well, I'm thinking of buying two of the amps (either Greg's or Aska) to act as "monoblocks" with my speakers (i.e., I'd run the highs/mids with one channel and the lows with one channel). So, I'm interested in a comparison.

 

[AndrewT]

Hi,
I cannot see a reference in either the SIN BIN or TEXAS to Amp Guru being barred.

How did you find out? if true.

 

[ShinOBIWAN]

Hi,
I cannot see a reference in either the SIN BIN or TEXAS to Amp Guru being barred.

How did you find out? if true.

It says 'account disabled' near his avatar. Find one of his post's and you'll see. If he was active it would 'DIYAudio Member' and if he was sinbinned it would likewise say just that.

Perhaps a mod could clear up exactly what has happened to Greg.

 

[ShinOBIWAN]

these days, this topic is more like:

Bring Back That Greggy Ball

An externally hosted image should be here but it was not working when we last tested it.

Eh? What the....

Are you calling Greg a queen because I absolutely see no relevance to your post.

Or was it just a warning for folks about the effects of smoking crack and then posting on forums?

 

[jacco vermeulen]

there you go

Click me, i'll do anything for a buck.

 

[hifryer]

Greg Ball / Amp comparos

I vote for Greg to come back.



Also look forward to the upcoming comparos!

MOST important right test conditions so AKSA is not asked for more than 55W!!!! Speaker sensitivity and whole test system should be quoted.

cheers

 

[lineup]

Eh? What the....
Are you calling Greg a queen because I absolutely see no relevance to your post.

Everybody can not see everything. At least not at once .....
You can smoke whatever you want, ShinOBIWAN

 

[tja]

It says 'account disabled' near his avatar. Find one of his post's and you'll see. If he was active it would 'DIYAudio Member' and if he was sinbinned it would likewise say just that.

Perhaps a mod could clear up exactly what has happened to Greg.

If he was banned it would say 'banned', not 'account disabled'. Maybe he has disabled it himself?

Take

 

[SY]

Queen? Oh, lord.

"Speculation in the absence of data is a capital mistake," or so said my childhood hero, Sherlock Holmes.

As members, we have the obligation to follow the rules of the community, or we don't participate. Everyone has that choice- moderators and admins are no exception. Nor does being in the industry give one a free pass. Other industry participants seem to do fine under our strictures.

Now, what was the actual subject of this thread again?

 

[ShinOBIWAN]

Everybody can not see everything. At least not at once .....
You can smoke whatever you want, ShinOBIWAN

Ouch it must have hurt.

 

[ShinOBIWAN]

Now, what was the actual subject of this thread again?

Talking about the finer points of Greg's design in his absence?

 

[anatech]

Hi ShinOBIWAN,
It's just like any other amp discussion. The creators are not always here but it's still worthy of a talk.

I think it's good you can share your opinions and experiences about the equipment.

-Chris

 

[ShinOBIWAN]

Hi ShinOBIWAN,
It's just like any other amp discussion. The creators are not always here but it's still worthy of a talk.

I think it's good you can share your opinions and experiences about the equipment.

-Chris

I know Chris.

Its a true land of freedom that we live in.

 

[KLe]

Hi Greg
Its an excellent VASless design (unless, its hiding?), and, I have placed my order for a pair of your GB300D (300W Class AB MOSFET) amplifier module kits
Is a 300VA transformer, and +/-70V supply rails, per channel sufficient/ok I know of a nice +/-60V SMPS. Perhaps, I could change the PS to it at a later date.

thanks again
KL

 

[Miles Prower]

"Its an excellent VASless design (unless, its hiding?)"

Not really VAS-less since that function is incorporated into the first stage LTP by bootstrapping it for higher than usual gain. I've seen similar designs that accomplish the same thing by using active loads with the first stage LTP.

 

[AndrewT]

Hi Kle,
if you want to copy how the CHEAP manufacturers assemble their amps then go ahead and put in too small a transformer.
However if you want a reasonably balanced assembly then I recommend that you use a transformer with a VA rating =1.5 times the maximum output power i.e. 450VA.
GB300 is very efficient in terms of output power vs Vrail potential according to the designer/manufacturer.
On this basis +-70Vdc (2*50Vac) is far too high.
I would expect somewhere between +-60Vdc to 65Vdc to achieve your 300W into 4ohm. Try to find a pair of 2*45Vac 500VA transformers. If 45Vac are not available, it is easy to add extra windings to the secondaries to achieve the higher voltage. An advantage in adding extra turns is that the thicker wire in a 40Vac with the extra turns will have a slightly lower Isquared R loss than a plain 45Vac 500VA.

As an aside, the peak current into 4ohms is about 12.2Apk. I recommend +-2mF per Apk for your main smoothing capacitors. This requires +-25mF 75V per channel. If you use 40Vac then 63V caps will just do. Personally I would use +-3mF/Apk/channel