Hiraga "Le Monstre"

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#1,261
triode_al said:
It is to me of no problem to have a higher Idss value and a lower R2 R3, but I may remind that Hiraga preferred the lower Idss version of 2SK170BL and 2SJ74BL.
I like to think about it as follows: The amplification with a lower R2R3 is also lower (relationship of R2 R3 and the 10 ohm source resistor). But I'm not sure the math works like that.
And a lower Idss of 2SK170BL and 2SJ74BL is hard to find.

So my suggestion: stick to it and adjust to 700 mA - that works great.
Click to expand...

The lower amplification is a slight problem, as the two channels are asymmetrric then due to different resistor values. I can fix it with a potentiometer in front of the loider channel. It does seem a bit weird though to have two channels that physically have different circuits?
 
#1,264
yoshisoakland said:
The lower amplification is a slight problem, as the two channels are asymmetrric then due to different resistor values. I can fix it with a potentiometer in front of the louder channel. It does seem a bit weird though to have two channels that physically have different circuits?
Click to expand...

Amplification will not change between channels when changing the Rsource, as amplification is laid down in the 10ohm/220 ohm.
The difference might be a slight structure difference in harmonics.
 
#1,268
Hi,

I'm looking for suggestion for the small BJT and drivers , here is my line-up arrangement ;

2SK170/2SJ74 (BL)
BC550/BC560
Drivers...see below
NJW0281G /NJW0302G

For drivers how about using
- BD139G/140G or
- (BC550/BC560 or BC327/BC337) with TO-92 heatsinks.
Would the BD139G be better sounding vs BC550 ?

I received a stereo set (Jim's Audio which uses all original transistors except for outputs) from a friend as a gift. I'd like to be able to use other transistors besides the JFET which I want to keep in the circuit.

I have access to many NOS BJT, if you have any recommendation please share and I'll look if I can find some for me and to share.

BR,
Eric
 
#1,272
This might be of generall interest, THD vs different supply voltages for the Le monstre.
 

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#1,277
Hi everybody!
I have just completed my build of this le monstre 8w amp, it sounds great 🙂 but i have a challenge with input sensitivity. I have to crank my preamp to max to get decent volume from speakers.
I have used original parts except the k170Y/j74Y, these are of GR ratings. and the trimpot is 200 Ohm instead of 100 Ohm to get right Bias setting.

Any suggestions how to overcome this challenge?
 
#1,280
Thanx 🙂 There's a lot of posts in this thread and i haven't read them all :s
So i suppose i lose 5db in input gain by using the GR ratings, but that shouldn't result in that low output volume should it?

I use a Yamaha RXV1900 surround amplifier, i hook it up on pre out and use CD, HTPC, Vinyl record player with same result.

Think it's BIASed right? have aprox 1v across 1 Ohm resistor and 1,69v across 1K R.
 
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