Burning Amp 2017 Updates Thread

wayne · 2017-11-14 4:26 am

Tom V said:
Someone who was there for the whole of Wayne Colburn's presentation should say something about the headphone amp. Two or three of them with different active devices were available to audition in the Pass room. Boards should be available in the DIY Audio Store soon.

Did I hear that this could double as a pre-amp as well?

Sure can with <.1 Ohms out it will drive cables very well. I left some things out of the presentation but 6L6 will get them in the guide. I need practice at these things.

One more item from Nelson Pass's presentation. There will be another round of devices for the Sony VFET amp available through the DIY Audio store. They had kept a large number back as spare parts, but since no-one has been able to break one a large portion of the "spare" parts will be released.

russbutton · 2017-11-14 5:30 am

2017 Burning Amp

The link below is a pretty complete set of photos from the 2017 Burning Amp.

http://russbutton.com/Russ/audio/2017BurningAmp/

One more comment... When I got to Burning Amp at Fort Mason, the parking lot was full. So I parked nearby in the lot next to the boat yard. I didn't see the sign saying that it was permit parking only. All I saw was there was almost no place to park and everyone was parking there.

Got a ticket that's going to cost me $179.

I will *NEVER* go to Burning Amp again if they continue at Fort Mason.

2 picoDumbs · 2017-11-14 6:04 am

Nice one Wayne.

2 picoDumbs · 2017-11-14 10:09 am

Soundhappy said:
crossovers : XL mini, XL mini with Sub + analogue equaliser
speakers : SAL OB etc. Incredible good Mr Pass superb work
Photos and schematic courtesy of First Watt

If Papa has done a crossover specifically for the LX mini, that sounds like a pretty bloody good endorsement. I'm seriously tempted to build the LX mini now.

woody · 2017-11-14 11:10 am

I know those of you who attended may have come away with a freeby or 2 but what about us who couldn't go ? Well if you live in the USA and couldn't go I may have a deal for you. There was some discusion here about the triode like curves of the IRFPS3810PBF devices and when I saw a super deal on these devices I pickedup a few of them. So for readers here who want to try a couple I have a few sets of 3 for FREE . Why 3 ? well one always needs to have a spair . Please USA only ! Offer void after nov 24 ( After thanksgiving I put on my scroudge cap. )

vdi_nenna · 2017-11-14 3:52 pm

Little confused about new ACA and DEFiSIT amp.

Is new ACA less power at 4.5w vs original ACA with R15 update at 6w?
Is it called ACA 1.1 or 2.0? Does 1.1 indicate a minor revision?

Does DEFiSIT use only SIT-1? I suspect it can use Sony VFETs?

thx.

Vince

koja · 2017-11-14 4:19 pm

I share the confusion about the new ACA(s). like I mentioned on the previous page the specs seen earlier looked different:
http://www.diyaudio.com/forums/pass-labs/310169-m2-story-3.html#post5155039

but I guess all will be made clear in due time; just give the folks a chance to rest after a busy weekend.

Tom V · 2017-11-14 4:28 pm

If I remember correctly, the new ACA 1.1 is closer to 10 watts with the 24V power supply. It has a new board layout for the new case, and some revisions to resister values, but is otherwise the original circuit.

vdi_nenna · 2017-11-14 4:56 pm

Tom V said:
If I remember correctly, the new ACA 1.1 is closer to 10 watts with the 24V power supply. It has a new board layout for the new case, and some revisions to resister values, but is otherwise the original circuit.

Yes, that still sounds like the R15 update with a larger power supply.

No big thing. I'm just curious about the higher powered version of ACA.

thanks,

Vince

Nelson Pass · 2017-11-14 6:02 pm

mordikai said:
Sounds like the B1 Korg would be great for an F4!

Unfortunately the sweet zone for the Korg circuit as shown is less than 2
volts out, so you would want to think of some means of getting more gain.

I'm working on a nice Fet gain stage that might do that for you, and driving
a transformer for voltage gain is an option.

Apart from that, I find the Nutube to be a good match for amplifiers with 3rd
harmonic character, which is most push-pull types, including F4.

Nelson Pass · 2017-11-14 6:06 pm

BTW, I thought that this year's BAF was probably the best. Lots more people
bringing and demonstrating their projects, which was something we were really
trying to achieve.

Volunteers and management were first rate.

Congratulations all around.

mordikai · 2017-11-14 6:08 pm

Nelson Pass said:
Unfortunately the sweet zone for the Korg circuit as shown is less than 2
volts out, so you would want to think of some means of getting more gain.

I'm working on a nice Fet gain stage that might do that for you, and driving
a transformer for voltage gain is an option.

Apart from that, I find the Nutube to be a good match for amplifiers with 3rd
harmonic character, which is most push-pull types, including F4.

got it. Thanks!

Nelson Pass · 2017-11-14 6:14 pm

I forgot to mention, the stuff in my talk will be written up and put on line
soon, in several installments.

woody · 2017-11-14 7:39 pm

I offered some free IRFPS 3810pbf devices earlier today sorry they have all been spoken fore. I know I should have offered then in the swap meet but just wanted Pass fans to ask for them. So sorry all gone.

2 picoDumbs · 2017-11-14 7:40 pm

vdi_nenna said:
Is new ACA less power at 4.5w vs original ACA with R15 update at 6w?
Is it called ACA 1.1 or 2.0? Does 1.1 indicate a minor revision?

Does DEFiSIT use only SIT-1? I suspect it can use Sony VFETs?

thx.

Vince

ACA 1 never did 6W on 19V supply, more like 5.5W. Nelson said ACA 1.1 does 1% distortion at 4.5W. They both swing the same voltage if powered by 19V and they can be made to swing more on a 24V or 30V supply.

Tom V said:
If I remember correctly, the new ACA 1.1 is closer to 10 watts with the 24V power supply. It has a new board layout for the new case, and some revisions to resister values, but is otherwise the original circuit.

With 24V supply power is about 8W.

vdi_nenna · 2017-11-14 9:17 pm

ACA 1 never did 6W on 19V supply, more like 5.5W

I might have exaggerated because I'm using as 20.5v to 21v secondary. Not sure where the voltage drop lands it.

Can't believe it's only 5w. My speakers are not efficient at all.
This is why the new version is so interesting to me.

gibber · 2017-11-14 9:32 pm

I can't help but feel this is a thread on a trade show...
Am i too german(e) w/ respect to diy roots perhaps?

All the best,
Ralph

planet10 · 2017-11-14 10:45 pm

vdi_nenna said:
Can't believe it's only 5w. My speakers are not efficient at all.
This is why the new version is so interesting to me.

Same here.

dave

Michael Rothacher · 2017-11-14 11:03 pm

gibber said:
I can't help but feel this is a thread on a trade show...
Am i too german(e) w/ respect to diy roots perhaps?

All the best,
Ralph

Burning Amp is not a trade show, it is primarily a patron-supported, volunteer run show which celebrates DIY. A lot of good people give their time and treasure to make it possible.

2 picoDumbs · 2017-11-15 12:02 am

vdi_nenna said:
I might have exaggerated because I'm using as 20.5v to 21v secondary. Not sure where the voltage drop lands it.

Can't believe it's only 5w. My speakers are not efficient at all.
This is why the new version is so interesting to me.

ACA is a very nice amp. Everyone should build one.
If you already have a diy firstwatt amp, it makes for a great second amp for bedroom or office.

Burning Amp 2017 Updates Thread

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