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SE 6L6 power amp, 12AT7 driver (design by Suncalc)
http://diyaudioprojects.com/Forum/viewtopic.php?f=9&t=5731
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Author:  Geek [ 09 Jan 2017, 02:28 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

mwhouston wrote:
Gregg. I nearly fell over, my wife liked it!


Woah! :eek:

High WAF is nearly impossible, congrats!

I am thinking.... small speakers in the ends, simple jack input.... "portable" tube player amp. Would be perfect for me in my store, as I'm hopping from my main bench to desk to benches 2 and 3 to front counter... :D

Author:  mwhouston [ 09 Jan 2017, 05:50 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

I'm going to use seperate bottle boxes for the speakers. Hard to believe the small drivers are 95db efficient. Great for a power amp like this one.

http://www.altronics.com.au/p/c0635-100mm-15w-8-ohm-high-efficiency-paper-cone-speaker/

Click on the specs tab.

Author:  mwhouston [ 09 Jan 2017, 06:08 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

It appears the driver I have (not in the link above) is only 87db effcient. The one above is 92db.

Guess I'm off to the store tomorrow to get the one above. Or I could try the 87db version I have. Or both. They are cheap enough.

Here is the driver I have. What are your thoughts? Go down to the specs tab.

http://www.altronics.com.au/p/c0626-100mm-15w-8-ohm-paper-twin-cone-speaker/

Author:  gofar99 [ 09 Jan 2017, 09:20 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

Hi Mark, an interesting end to the project...spouse approval. Wow. Maybe I could hide all my gear in the fireplace (useless in Arizona) and just set up something that looks like that for show. Just have the heaters powered. I can control everything except the turntables and reel to reel remotely anyhow. ....but then my plans to turn the fireplace into a super sub woofer would not be viable. :lildevil:

Good listening
Bruce

Author:  Geek [ 09 Jan 2017, 16:47 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

gofar99 wrote:
Maybe I could hide all my gear in the fireplace (useless in Arizona)...


Unless we send you the odd "arctic outflow" like that one that froze everything all the way, halfway into Mexico about 10 years ago ;)

Author:  Suncalc [ 09 Jan 2017, 18:25 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

Geek wrote:
High WAF is nearly impossible, congrats!
The only amp I've ever built with appreciably high WAF was the 6EM7 Vertical Amp. One day I hope to succeed again.

Congratulations Mark! You set a high bar to which we may aspire. :D

Author:  mwhouston [ 09 Jan 2017, 23:17 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

Suncalc wrote:
Geek wrote:
High WAF is nearly impossible, congrats!
The only amp I've ever built with appreciably high WAF was the 6EM7 Vertical Amp. One day I hope to succeed again.

Congratulations Mark! You set a high bar to which we may aspire. :D

Shucks!

Author:  Gio [ 09 Jan 2017, 23:29 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

mwhouston wrote:
Guess I'm off to the store tomorrow to get the one above. Or I could try the 87db version I have. Or both. They are cheap enough.

Hey Mark. I think you will want to pick up the other pair, for the sensitivity, and also the lower Fs.

Cheers

Author:  mwhouston [ 10 Jan 2017, 00:53 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

Gio wrote:
I think you will want to pick up the other pair, for the sensitivity, and also the lower Fs.

Have to agree. I just received a 15W Class D amp for $5. I'll set up the drivers I have to work with that and purchase the more efficient ones for the 6L6 amp. I have some Plessy bullet metal horns to go with the more efficient drivers to extend the frequency range.

Author:  mwhouston [ 11 Jan 2017, 22:47 ]
Post subject:  Re: SE 6L6 power amp, 12AT7 driver (design by Suncalc)

It lives. I had a terrible time trying to get the HT to anywhere near 300V the way I was doing it.

There is a twin secondary filament tranni wired for twelve volts. The 6L6 filaments are wired inseries and the 12V sits across that. The 12AT7 also uses this heater setup.

Gather some small stones and limber up your throwing arm.

In the end to get 280V of double filtered HT I used direct mains (240V). Commence throwing. The chassis is wooden and the filament tranni is earth and the whole amp fused. No chance of the chassis going live.

I used a 1A rec bridge - 47uf - 470ohms - 100uf - 150ohms - 470uf. With moderately low effciency speakers there is no hum. Yet to be tried on the Beymas. The total current draw is 89mA and Vg is 20V on the 6L6s. These are well under what Matt thought they would be.

The amp sounds OK on a short listen. I'll report back with more images and listening notes.

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