F6 Illustrated Build Guide

[Wishborn]

So I have ordered transformers and they are on their way as of last night.
My speakers is 4ohm, I have read somewhere that there are components that needs to be changed,
Can someone put on a short notice on witch components I should change.

Lastly, does anyone have two sets of the q2 and q3 for sale. Seems like overkill to order 8 of each.

 

[silasmellor]

I use stock configuration for 4 oh dynaudio excite x16s and that works fine, if that's of any use.

 

[Wishborn]

Yes i recon it is, i just remember i read somewhere about zeners that probably would need changing.

 

[palstanturhin]

Yes i recon it is, i just remember i read somewhere about zeners that probably would need changing.

Zeners, minimum voltage 5.6
6.2v or 6.8v recommended...

 

[silasmellor]

I used 6.8v if I remember correctly but I can check. I thought that was related to overall bias of the amp and not dependent on the speaker resistance?

 

[Wishborn]

For the bias it probably does not matter but for the temp it should

 

[fabrice63]

I am looking for some advice in placing the TL431 in the F6 schematic , as Zener replacement , any thought are welcome

.

 

[Zen Mod]

no need for that

either LEDs or zener are absolutely perfect for task

 

[fabrice63]

I know zener or led do the job , but i like to do that mod , my concern is about the reference for the voltage regulation.
.

 

[Zen Mod]

then learn how and make it for your own pleasure

 

[fabrice63]

I am gonna

 

[kbergsson]

Hi I have just started to gather parts for a F6 build. I have heard/read so many positive comments on the First Watt amps from people with effective speakers and horns and would like to try them on my Altec A5 VOTTs.
I have ordered trafos from Jensen, transistors and prints from the diyaudiostore, but they dont have any jfets (MATCHED LSJ74/LSK170 JFET PAIRS ) and no info regarding awailability. Is there an alternative, reliable source for these jfets?

Regards
Kjartan

 

[silasmellor]

You can try liubincalvin over at the vendors bazaar.

 

[fabrice63]

I have made business with him , the guy is fully reliable

.

 

[kbergsson]

Thanks.

 

[Mixi]

Hi! I'm looking for a new amp project and the F6 looks very tempting to me. I understand that it has a gain of 14 db. Would that usually require a pre-amp to add some gain?

I currently run a neurochrome lm3886dr with a gain of 26 and a phono pre. I rarely turn up the volume higher than 50% (12 o'clock). Can any conclusions be drawn from this comparison?

best,
michi

 

[silasmellor]

Not sure i can answer the gain question properly for you, but don't forget that your LM3886 amp outputs 45W into 8ohm, where F6 is 25W, which will also impact overall levels. Overall it will probably be less loud. I use an F6 with 87db/w dynaudio (4ohm) speakers and i never turn the pre all the way up, if that's any help.

 

[PJN]

I have a couple of Mauro Pensa Myref chip amps that are also based on the lm3886, I think that their gain is near that of yours. I've never heard a neurochrome chip amp, but I built an F6 and it was a very clear step up from the Myref, no contest at all. I think you will need a good preamp to make it shine though. The F6 is an easy build and sounds great and can drive some surprisingly big speakers, I'm using mine to drive some 3 ways. A really nice pre that is available now is the Salas Dcb3 that Teabag has a group buy for.

Good luck,

Paul

 

[wdecho]

With my horns it had sufficient gain just using my B1 buffer that has no gain. Another issue would be size of room and listening level desired. With conventional speakers a pre with gain would probably be a necessity for most. My experience with F6 is it sounds very similar to F5 which is an easier less costly build. No input transformer to purchase.

 

[ColinA123]

My F6 runs from a passive pre. (10k ladder stepped attenuator)
and is fed into Jericho horns.
Plenty loud enough in my large listening room.