[L0rdGwyn]

Would love to open up the covers of both LF339 and LF339i later for photoshoot. It is however as hot as the previous LF339, maybe a bit less hot. The 2 semi naked power transformers are better looking in real life. I use to think that the old model looks better but my mind is changed now after seeing this LF339i in the flesh. It is definitely better looking than the LF339. The 2 handles are very smooth and nice to touch even if they serve no purpose. Just add to the La Figaro 339i unique look.

If you post photos of both circuits, I will tell you what I see that is different (or isn't), I'd imagine they are very similar. Everyone loves a naked transformer

 

[Galapac]

The 2 handles are very smooth and nice to touch even if they serve no purpose. Just add to the La Figaro 339i unique look.

The handles are used if you have a rack, easier to pull out from the front, hang a carabiner off them, etc.

 

[Galapac]

If you post photos of both circuits, I will tell you what I see that is different (or isn't), I'd imagine they are very similar. Everyone loves a naked transformer

Here are some shots of the standard 339i -posted by @adeadcrab :

https://www.head-fi.org/threads/la-figaro-339.502306/post-15844653

 

[UntilThen]

Nice! Btw what is the Forza cable You are using? Is it the same cable plugged to La Figaro and to Audeze?

They are both Forza cables. On Audeze LCD-3f, I use Claire Hybrid HPC + the Noir Hybrid HPC pig tail. The Noir pigtail was chosen because my Hekse has Noir Hybrid HPC cable so it will be matching.

 

[UntilThen]

If you post photos of both circuits, I will tell you what I see that is different (or isn't), I'd imagine they are very similar. Everyone loves a naked transformer

I will but it will be much later because of work. I don't normally like naked transformers but I will make an exception for this lovely .... was going to say lady but it's Figaro.

The handles are used if you have a rack, easier to pull out from the front, hang a carabiner off them, etc.

The handles are so smooth I keep touching it !!! This should be mandatory on every amp.

 

[L0rdGwyn]

Here are some shots of the standard 339i -posted by @adeadcrab :

https://www.head-fi.org/threads/la-figaro-339.502306/post-15844653

Comparing these two photos...

339



339i



The only obvious change is they have added an additional RC to the B+ filter circuit. In the Darkvoice (and as far as I can tell, the La Figaro 339), the filter goes:

CRCRC-CRC

Which I thought was peculiar as the fourth and fifth capacitors in the filter are directly connect to one another, meaning they are in parallel, meaning the capacitance is additive, there is no filter. I wondered to myself "why didn't they throw a resistor between the two to decouple the capacitors?" There is really no downside, it will just add additional 120Hz noise suppression. Well seems they thought the same thing because they added the resistor so now it goes:

CRCRCRCRC

The mains transformers appear to be larger, so perhaps there is additional B+ and the bias points have been altered? Cannot say without measuring it. They might have altered the output capacitance, but it isn't obvious, can only spot 6.8uF caps but I believe there are others hidden in the center transformer shroud.

By and large though, the circuit is the same.

 

[UntilThen]

While I enjoy your dissection of LF339 and LF339i, I'm a subjective person. My ears tells me that these are just beautiful sounding amps. Anyway if Yuking could reply well in English I'm sure he would because after all he is the designer and creator of Le Figaro.

Note:- Yuking have always mentioned that he could do a customised LF339i and @tintinsnowydog have a nice specimen of it. So one day if possible I'll wish to hear his customised version with mine.

 

[tintinsnowydog]

What kind of upgrades are people thinking of making to their La Figaro 339? I was looking over the circuit this morning, it is very similar to the Darkvoice, the major differences being the dual mono power supply, the paralleled sections of the output tubes, the triode-strapped pentode driver, and increased output capacitance, which the Darkvoice badly needs.

If you post photos of both circuits, I will tell you what I see that is different (or isn't), I'd imagine they are very similar. Everyone loves a naked transformer

I have a custom-built 339i with some small changes to the circuit, namely fixed bias on the driver tubes and diode rectification of the power supply. The output capacitors can be upped to 120uF (I stuck with 100uF due to size constraints), the coupling caps can be upgraded. The caps in the power supply can be upgraded (mine has BHC ones). Resistors can be upgraded to tighter tolerances (I have Caddock ones). Aside from that I don't think there is too much in the topology to change. Maybe it is possible to CCS the tubes? If you'd like I can send photos of my 339i circuit to you

 

[L0rdGwyn]

I have a custom-built 339i with some small changes to the circuit, namely fixed bias on the driver tubes and diode rectification of the power supply. The output capacitors can be upped to 120uF (I stuck with 100uF due to size constraints), the coupling caps can be upgraded. The caps in the power supply can be upgraded (mine has BHC ones). Resistors can be upgraded to tighter tolerances (I have Caddock ones). Aside from that I don't think there is too much in the topology to change. Maybe it is possible to CCS the tubes? If you'd like I can send photos of my 339i circuit to you

Cool! Fixed bias on the driver tube? Curious how that is being accomplished. CCS is possible, I will do it on the Darkvoice (well, gyrator to fix the DC-coupled voltage). CCS sets the current and the tube finds its voltage. Gyrator sets the voltage and lets the tube find its current, better for DC coupling as the bias point of the output tube is now dependent on the plate voltage of the driver, they are interdependent. Feel free to send a photo, I'd be happy to look it over. Anywho, don't want to hijack the thread dissecting amplifiers, I will take my leave!

 

[tintinsnowydog]

Cool! Fixed bias on the driver tube? Curious how that is being accomplished. CCS is possible, I will do it on the Darkvoice (well, gyrator to fix the DC-coupled voltage). CCS sets the current and the tube finds its voltage. Gyrator sets the voltage and lets the tube find its current, better for DC coupling as the bias point of the output tube is now dependent on the plate voltage of the driver, they are interdependent. Feel free to send a photo, I'd be happy to look it over. Anywho, don't want to hijack the thread dissecting amplifiers, I will take my leave!

Here is the custom circuit, the fixed bias is via a 1.5V battery. Cathode follower and coupling caps are under the board at the front. Your amp and circuit knowledge is always welcome! If you want to discuss further PM xmdkq and myself I can help translate

 

[L0rdGwyn]

Here is the custom circuit, the fixed bias is via a 1.5V battery. Cathode follower and coupling caps are under the board at the front. Your amp and circuit knowledge is always welcome! If you want to discuss further PM xmdkq and myself I can help translate

Very cool! Battery bias it is then, keeps an electrolytic out of the signal path, should improve the sound. Most people do not realize it, but the last cap in the power supply is in the signal path in these single-ended amplifiers, so the BHC caps in this case. Another method to remove the cathode bypass cap, other than fixed bias is to use an active load, again like a CCS. The effect on the internal resistance leaving the cathode degenerated is minimized in this case, so you can get away with leaving it unbypassed. Can also take the signal output from the source of the bottom CCS FET, making the effect on the internal resistance irrelevant, although this technically puts a transistor "in the signal path", but for those that are not afraid of a little sand assistance, this can be very beneficial to the circuit especially if you have a difficult-to-drive output tube, like a 300B.

 

[hp4fun]

Figaro has landed and in a word, it's amazing. Quality of fit and finish surpass my expectations on this new model. I am totally caught off guard. Volume knob turning is very smooth !

1st impression with RCA 5693 and Tung Sol 7236 is you don't need better because better is already here. Any notion of me wanting to upgrade this LF339i is out of the window now. It's simply gorgeous sounding and no hum, no hiss, no noise until 1 o'clock. That is very good !

Not having my previous gorgeous silver LF339 to compare, I'd say I really love this tone but I've not use Tung Sol 7236 in my previous LF339, only in my previous, previous version which is @Bruc3 version which I sold to him. Now my previous version is going to @xtiva and current version will stay with me for eternity.

So if you haven't already gotten a LF339i (the latest model with preamp) and you're on the fence, run and don't walk to get one !

Your silver brother. 7236+5693 has a different taste than the CV4079+EF86. I love them both and don't want to compare.

And just checked ebay. $200+ for one 7236? Seriously?

 

[UntilThen]

Anywho, don't want to hijack the thread dissecting amplifiers, I will take my leave!

You probably took my message the wrong way. When I say 'While I enjoy your dissection of LF339 and LF339i, I'm a subjective person.' I mean exactly that. That I am a subjective audio enthusiast - would never call myself an audiophile - that's being too serious. I listen and if I like I buy it. No other hidden connotations behind it. That's the way with my Yggdrasil. I'm aware that it doesn't measure well but that doesn't matter to me because it sound beautiful.

I was in a hurry to go out for my lunch appointment and only saw this and thought I should clarify myself.

It's good to see @tintinsnowydog custom amp insides shown again. Looks beautiful to me. Again from a non technical background. I'm a software person. My only interest in hardware is using it. If my LF339i insides is half as good as this, I'd be very happy. So this weekend I will open it up. Not him or her but it. An amp has no gender as far as I'm concerned.

 

[UntilThen]

Your silver brother. 7236+5693 has a different taste than the CV4079+EF86. I love them both and don't want to compare.

And just checked ebay. $200+ for one 7236? Seriously?

What if I told you that my pair of Tung Sol 7236 are free including 2 pairs of RCA Red Hots 5693. That's right, my friend included them for free because I recommended the LF339i to him and he likes it. However in culling his amps he had to let the LF339i go and he said it went back to the right person - someone who loves it despite all the other more expensive tube amps I have.

I will get your CV4079+EF86 - well I already have the EF86 so it's just the CV4079 plus adapters. Then I'll let decide for myself if these are better than Tung Sol 5998, Tung Sol 736, Bendix 6080 and GEC 6080. In 3 months time, my GEC 6as7g will return to me.

 

[UntilThen]

This is where you buy Cetron 7236. Grab while it last because I'm sure it will go fast after this.
https://tubeworldexpress.com/collections/power-tubes/7236