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"Lacewood" Amp V2.0
http://www.diyaudioprojects.com/Forum/viewtopic.php?f=9&t=5736
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Author:  Soundbrigade [ 16 Nov 2018, 02:39 ]
Post subject:  Re: "Lacewood" Amp V2.0

Isn't the 45 an equivalent to 10Y?! I got a pair of these but I already have to 750mW amps ...

Author:  Chris65 [ 16 Nov 2018, 07:14 ]
Post subject:  Re: "Lacewood" Amp V2.0

Only in that they are both directly heated triodes, otherwise not similar. 801a is a 10y with higher ratings.

Author:  Suncalc [ 16 Nov 2018, 18:54 ]
Post subject:  Re: "Lacewood" Amp V2.0

lowhifi wrote:
I will like to build the Electra-Print audio 45 amp using the power supply of the Lacewood 2.0
https://www.electra-print.com/45silver.php Any worries.
Well, for starters, the Lacewood 2.0 supply has no 2.5v filament supplies, the 6.3v winding is overkill for a couple of 6SN7s, and the B+ will be quite a bit lower than the Electra-Print supply. Other than that, no worries.

Author:  Suncalc [ 25 Nov 2018, 13:38 ]
Post subject:  Re: "Lacewood" Amp V2.0

On the advice of someone I respect, I performed an experiment this morning. I tried out the KT-88 in this amplifier. It did have a nice sound. However, unfortunately I only have one working KT-88 currently in my possession. As such, I had to run the amp in monaural mode. But I was able to take some measurements on that channel. Here are the numbers:
Attachment:
Lacewood V2 KT-88 Summary.png

So if anyone has completed the Lacewood V2 and happens to have a set of KT-88s handy, could you give us your impressions?

Author:  Suncalc [ 22 Dec 2018, 20:17 ]
Post subject:  Re: "Lacewood" Amp V2.0

Suncalc wrote:
So if anyone has completed the Lacewood V2 and happens to have a set of KT-88s handy, could you give us your impressions?
Ah... No. DON'T DO THIS!

I just switched on the Lacewood V2.0 for a listen and evidently I smoked a cathode bias resistor. After doing some analysis I have concluded that this is a likely outcome for anyone trying the KT88 in this amplifier. And if you run it in Stereo mode, you'll over tax the power transformer as well.

So stick with the 6V6, 6L6, 6W6, & 6F6 for this amp. I hope I didn't lead anyone astray. :blush:

Author:  john55 [ 23 Dec 2018, 05:22 ]
Post subject:  Re: "Lacewood" Amp V2.0

That's saved me a few euros. I was going to order some KT-88s in the new year.

Author:  lowhifi [ 10 Mar 2019, 07:26 ]
Post subject:  Re: "Lacewood" Amp V2.0

Finally my second Lacewood 2.0 is functionnal, the enclosure still need work but at least i can enjoy.
I finally buy a pair of Tango H-5S for the high frequency in my active set-up. Sorry for the poor quality of the picture.
Image

Author:  Chris65 [ 10 Mar 2019, 16:34 ]
Post subject:  Re: "Lacewood" Amp V2.0

Suncalc wrote:
lowhifi wrote:
I will like to build the Electra-Print audio 45 amp using the power supply of the Lacewood 2.0
https://www.electra-print.com/45silver.php Any worries.
Well, for starters, the Lacewood 2.0 supply has no 2.5v filament supplies, the 6.3v winding is overkill for a couple of 6SN7s, and the B+ will be quite a bit lower than the Electra-Print supply. Other than that, no worries.


Don't see why it wouldn't work, perhaps with some small changes.
The Electra Print circuit requires about 320V B+, change out the rectifier tube for a lower voltage drop type (5AR4, 83-V) & adjust the dropping resistor in the Lacewood supply, should get you close.
The 45 filaments are powered by the 6.3V supply, rectified/filtered for the required 2.5V.

Author:  mwhouston [ 10 Mar 2019, 17:13 ]
Post subject:  Re: "Lacewood" Amp V2.0

You can purchase RCA right angle adapters. I use them in a preamp where the RCAs are mouthed on the top. Could look a little neater. But good build.

Author:  Suncalc [ 10 Mar 2019, 19:02 ]
Post subject:  Re: "Lacewood" Amp V2.0

john55 wrote:
That's saved me a few euros. I was going to order some KT-88s in the new year.
Maybe I'll do a KT88 SE-UL bias optimization study when I'm through with the 6L6. I think it might be interesting.

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