Nice. Have to listen more to tell you their exact traits.
Salas,
I'm going to make it drive the Pass Lab F4 power amp. Can you tell what kind of gain ( db ) it can provide?
Thanks
I'm going to make it drive the Pass Lab F4 power amp. Can you tell what kind of gain ( db ) it can provide?
Thanks
With a 1V P-P input and about 6V P-P output (volume control at max), this is the distortion it charts. Only second harmonic above the grass. 3rd etc are missing in action. Also, otherwise much possible 50 & 100 Hz hum peaks, are missing in action too with the regulator used.
At half the volume rotation, it gives 0.07% THD and 0.051% IMD. I am not sure if the percentages are right or actually lower (I used an IBM Thinkpad which loops 0.05% by itself), but the shapes are correct.
At half the volume rotation, it gives 0.07% THD and 0.051% IMD. I am not sure if the percentages are right or actually lower (I used an IBM Thinkpad which loops 0.05% by itself), but the shapes are correct.
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Salas,
I've collected all parts I'll need for the project with 2 very nice nos philips 6v6.
I'd like to make use of all other parts I have in hand. 350-0-350 120ma tranny, cv378, 32H choke and couple 100uf Elna Cerafine and 50k 25w breeder but don't know if the tranny is too big?
Albert
I've collected all parts I'll need for the project with 2 very nice nos philips 6v6.
I'd like to make use of all other parts I have in hand. 350-0-350 120ma tranny, cv378, 32H choke and couple 100uf Elna Cerafine and 50k 25w breeder but don't know if the tranny is too big?
Albert
Looks like too big for voltage. But there are always resistors to calculate voltage drops to suit. Keep in mind that all you need is a 340V, clean B+ under load. There are many different ways to skin a cat.
I'm looking for another tranny for this pre, 300-0-300 sounds more suitable.
Have you ever thought of making it a balanced pre?
Have you ever thought of making it a balanced pre?
Yes, its more suitable.
No, I haven't tried to make a balanced pre. My best source is my humble TT with Denon DL-160 through my Jfet Riaa design. Its single ended. But my Benchmark DAC-1 has balanced outputs too, and I can always design a new Riaa which accepts the cartridge balanced for current amplification...hmm don't put new ideas to me. I just finish my experiments on cascoding my Jfet RIAA...🙂
No, I haven't tried to make a balanced pre. My best source is my humble TT with Denon DL-160 through my Jfet Riaa design. Its single ended. But my Benchmark DAC-1 has balanced outputs too, and I can always design a new Riaa which accepts the cartridge balanced for current amplification...hmm don't put new ideas to me. I just finish my experiments on cascoding my Jfet RIAA...🙂
here is a preamp I builded use 5686 pentode.
the 5686 pentode is similar to 6V6/EL84.
the DIY report are post to my homepage below:
http://my.coolala.net/showpost.php?board=87633&bdct=97559&id=2907609&page=1
the 5686 pentode is similar to 6V6/EL84.
the DIY report are post to my homepage below:
http://my.coolala.net/showpost.php?board=87633&bdct=97559&id=2907609&page=1
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Hello Salas----
How good is the 6v6 pre compared to Conrad Johnson act2 pre-
i have try that --in my system--but it vas to boring---is there good life sound in yours??
is the pre easy to build for a man there only have made fet build-eks. Erno Borbely-?
best regards
Bjarne
ps---it is first time, i post something on forum.so i hope i do it right.
How good is the 6v6 pre compared to Conrad Johnson act2 pre-
i have try that --in my system--but it vas to boring---is there good life sound in yours??
is the pre easy to build for a man there only have made fet build-eks. Erno Borbely-?
best regards
Bjarne
ps---it is first time, i post something on forum.so i hope i do it right.
Salas - I'm just curious ..... you obviously are trying to find best CCS for your purpose , but - did you tried yet to cascode 6V6 itself ..... to ensure constant voltage operation of triode ?
bjt+mosfet wil suffice for that purpose , if not mosfet alone ....
bjt+mosfet wil suffice for that purpose , if not mosfet alone ....
beardman said:
Don't know about CJ.
Lifelike sound there is in it, but handling 6V6 in a line pre without false enthusiasm in its sound takes caution in its mounting. Needs to be mechanically decoupled especially when actively loaded in full mu (gain=9.4). Its not a difficult concept to grasp at all, but it takes work. It has to be made with quality parts, and silent transformer if on same chassis. The chassis plays significant role. One general remark for a pre not to sound boring or aggressive in your system, is gain structure. There is just right or less or too much. Happily, the 6V6 trioded sounds excellent from cathode follower buffer arrangement, or medium gain with resistor loading, up to full tilt with active anode loading.
Zen Mod said:
Won't this increase the output impedance? If it remains acceptable, I can try.
*I really wanted to do that with valves and OPT, but the chassis is too nice and heavy so to hack and experiment. I will have to do experiments with 4 6V6s and the assorted psu and heating arrangements given the chance of making another new one and most probably with an HV shunt too.
**Meantime, THE BEST active loading to my ears is an electronic choke. Recommend you to try on some project of yours. Alas, I have too sensitive speakers for the gain I get...
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Salas said:
not really - you can look at mosfet cascode as on follower 😉
sort of ....
point is that properly biased cascode is invisible , sound wise ....
Salas said:
yup - but you already know for my opinion about shunt regs
... you'll have benefits , even with all those CCS-es everywhere 
Salas said:
principle is ( at least on that schematic , where you forgot to draw point between 3. and 4. led ... hehe) same as with Geek/P10/forgivemeifIforgotsomeone "generic universal CCS-es" , where you have one current setting active element , cascoded with another one ....
look at my
LTP tail .... overall - fugly! , what else ?
😀
Zen Mod said:
Naah, I did not forget.😎 There has to be no connection there. 6LEDS turn on the lower Mosfet. The upper one has the top divider's resistor. If you connect, the voltage on anode will latch up at B+ level.
*This is constant voltage on DC, not constant current. Its a gyrator. Gives the benefit of the constant voltage anode by electronically simulating a large choke (e-choky?
).