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    Building, troubleshooting and testing of these amplifiers should only be
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    the safety precautions around high voltages.

help for E182CC linestage/driver

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I

inertial

Member
Joined 2004
finally....

Hi all,

I am sorry for the late reply but I'm very busy with an important loudspeaker project ( that is my expertise) for a obsessive friend, nearly incontentable :D

We have made a PCB for the 6N6P-I.
B+= 200 volt ( mosfet series regulated)
filaments: AC
anode resistor : 5,6K allen Bradley ( 95 volt across)
cathode resistor: 100 ohm allen Bradley ( about 20mA-each triode)
output cap : old Siemens mkp 1microF

Load: 100K with 1500pF in parallel

Gain: 10,6 times (unbypassed cathode)- 14 times ( bypassed)
-3dB at 40 Khz ( unbypassed cathode) - ( bypassed) 60 Khz

measurement are performed at 17,5 V out RMS undistorded :devilr:

This puppy looks incredible, THD are better than a cathode follower of 6922 ! :bigeyes:
I' m quite pleased for now.
Today I'll test microphonicity and start serious listen.

I want thanks you all kind guys and expecially Gordy for very precious help. Sure in future I'll need others suggestions again :cannotbe:

If all will be good, next steps 'll be a new PSU ;)

Cheers,
Paolo
 
I

inertial

Member
Joined 2004
Thanks Lars,

Yes I was suspecting a similar result. Not bad ,eh? ;)
Are those date precise or extimate?
Frankly I was expecting a little lower values for Zout but
measurement of -3dB point on high frequencies seems confirmate your statements.

I think this 6N6 have good gain and appreciable low Zoutput,
exactly what I need for drive my power follower.
Maybe I am wrong but there are not so many other tubes with these
carachteristics . 5842 ( not my taste), 6C45P ( not tryed).
What other?

Forgot to mentione that the two half-triodes are extraordinary good matched! :devilr:

Now I have fear to check microphonicity...........too beautiful to be real!

Cheers,
Paolo
 
I

inertial

Member
Joined 2004
Hi,

First bad surprise: one channel is very little microphonic :bawling:
I'm fanatic about not-microphonic, no need to explain other.
I have others 9 valves to test, very annoing!
I was too much well accustomed with my old sowtek 6922, zero microphonicity, maybe I' pretending too much.........

It is a pity, hovewar, the others "traditional" tests looks fantastic
for this 6N6P-I.

Cheers,
Paolo
 
I

inertial

Member
Joined 2004
the sound of 6N6P-I

after 10 hours of break-in ,

the sound is very different from my previous 6922 cthode follower :eek:
In short, I am amazed how good this 6N6 sound. In comparision , cathode follower is near unlistenable. Finally the entire system sound
full, hot, harmonic,dinamic .....it is incredible :D
I suspect 90% of this is due to the anode otput versus previously cathode output more than 6922 per se.
Maybe also the big current capability of the 6N6 is important to drive correctly my mosfet , I dont know:rolleyes:
Anyway I am relistening all my favourite albums just for pleasure
and they sound incredibily natural, like a monotriode with the brute force of a big solidstate :D



Cheers,
Paolo
 
I

inertial

Member
Joined 2004
Thanks SY,
I 'm not sure of your sentence, first because previously 6922 was designed by a very well regarded EE here in Italy ( no name because I do not want make polemic) , second because when I and my friend have tested it on the real load ( 100K- 1800 pf) , the "scope" show good performance up to 10-12 V rms. Quite sufficent IMO, output mosfet clip before that level.
Maybe I am a newbie and do not know what I am talking about, perdone me ! :D

I am glad too this puppy is sounding like a real triode :angel:

Cheers,
Paolo
 
I

inertial

Member
Joined 2004
Hi guys,

Just a curious comments after some listen ( 50 hours)
I have to disagree with myself and my previous statement about monotriodes!
I have noticed a huge difference bypassing the cathode resistor.
IMO this is because the 60Khz ( -3dB) versus the 40Khz ( -3dB).
Bypassed sound a lot better ie unbypassed sound "closed", incomplete. Imaging also suffer a lot.
I am not familiar with tech specifications so I have searched some data. Well, if I am right, 40 Khz of upper limit is considered "good" for
a SE triode amp. without feedback. Very good transformers .
So I am confused, am I missing something ? :confused:

Cheers,
Paolo
 
I

inertial

Member
Joined 2004
Hi again guys,

Yesterday I have made a decise improvement:
Swapped the electrolitic cathode bypass with a decent MKP, same value. Wow! :hot:
Incredible difference. Gained super dynamics on the mid-high zone,
grain is near zero, and the soundstage seems " stand-up" :bigeyes:
But this have altered the previous "equilibrium" so I had to adjust the
x-over levels to compensate :D just a bit of course :angel:
I am very happy . A friend have just listened and he ...:dead:

Next future plans are new PSU. Very important IMO.

shunt-Regulated or unregulated ? :confused:
CLC or LCLC ? :confused:
Have to learn a lot on this "subject" :cannotbe:

happy new year ,
Paolo
 
I

inertial

Member
Joined 2004
Hi Erwin,

5,6Kohm on the anode
100 ohm on the cathode ( bypassed mkp)
B+ 200V

-3dB at 60KHz with 100K 1500pF load
gain 14 times
distortion not visible on the scope up to 17-18 V RMS
Zout I don't know but presumed about 1400-1500 ohm

Maybe I would be try a more hard point of work, more tension and more current but I am not capable to read "6N6P-curves".

I am very satisfied. It SOUND !:cool:
Full, solid, robust,hot, harmonic-structured. This valve is very good!

Now I am thinking about PSU........would be 5R4WG Chatam, LCLC.............the problem is the input choke......very expansive and difficult to find one absolutely noiseless ( 40mA current):bawling:

Have to reflect........ :rolleyes:

Cheers,
Paolo
 
M

milen007

Member
Joined 2007
inertial said:
Hi Erwin,

5,6Kohm on the anode
100 ohm on the cathode ( bypassed mkp)
B+ 200V

-3dB at 60KHz with 100K 1500pF load
gain 14 times
distortion not visible on the scope up to 17-18 V RMS
Zout I don't know but presumed about 1400-1500 ohm

Maybe I would be try a more hard point of work, more tension and more current but I am not capable to read "6N6P-curves".

I am very satisfied. It SOUND !:cool:
Full, solid, robust,hot, harmonic-structured. This valve is very good!

Now I am thinking about PSU........would be 5R4WG Chatam, LCLC.............the problem is the input choke......very expansive and difficult to find one absolutely noiseless ( 40mA current):bawling:

Have to reflect........ :rolleyes:

Cheers,
Paolo
Click to expand...

Hi Paolo

thanks for the reply. pardon my ignorant, you are using 6N6P right?
do you use any input resistor on the grid?
do you use each tube per channel (parallel) or one tube for 2 channel?
what kind of amp do you use with this? as i have 100W hybrid amp and i am using diy tube preamp with gain of 8. there is too much gain in my system. Anyway to bring down the gain?
thx in adv

Tweeker said:
Spend that money on active regulation. Cheaper, lighter, and your more likely to hear a difference, DCR<1, some way less. Also, less mechanical and EMF noise headaches to deal with.
Click to expand...
hi Tweeker
newbie questions, can you please post some links about active regulation? any schematic? thx in adv

Erwin
 
I

inertial

Member
Joined 2004
milen007 said:


Hi Paolo

thanks for the reply. pardon my ignorant, you are using 6N6P right?
do you use any input resistor on the grid?
do you use each tube per channel (parallel) or one tube for 2 channel?
what kind of amp do you use with this? as i have 100W hybrid amp and i am using diy tube preamp with gain of 8. there is too much gain in my system. Anyway to bring down the gain?
thx in adv


Erwin
Click to expand...

HI Erwin,

6N6P-I indeed
820ohm grid stopper
half 6N6P for each channel
This is my amp ( I have a biamp, this is only for the mid+tw)
http://www.audiodesignguide.com/PowerFollower/index.html

your problem with gain maybe (can) has a symple solution:
what is the gain of your hybrid amp? 10 times, 20 times?
In this case IMO you can jump the preamp and put a pot on the input of your hybrid...
:D

Cheers,
Paolo
 
I

inertial

Member
Joined 2004
Tweeker said:
Spend that money on active regulation. Cheaper, lighter, and your more likely to hear a difference, DCR<1, some way less. Also, less mechanical and EMF noise headaches to deal with.
Click to expand...


Hi tweeker,
Thanks for suggestion but really now I have a regulated PSU ( series type with mosfet) : it works electrically perfect but the sound....mmmh, it seems to me a solid state preamp!:D
I have two options:
1) Shunt type regulator
2) unregulated, tube rectifier and LCLC .

I will have to try both! :bawling:

Cheers,
Paolo
 
M

milen007

Member
Joined 2007
hi Paolo

thanks for the reply. have you try the Salas' shunt reg? i am looking at it and may want to build one and saw you posting on that threat hence i assume you interested as well.

i have no idea bout the gain in my amp. i only know its rated 100w per channel. think the gain 7-8
 
I

inertial

Member
Joined 2004
Only 7-8 times?

It's strange if it employ tubes front-end....unless it use overall-feedback !:hot:
Do you have schematic? What brand-model it is?


About shunt reg, I am in very busy phase. I have a big speaker to
design and I am also thinking to swap digital source with another.
Big works. I have to programmate each phase to not make confusion!:D
Don't know when but I'll do it..........

Cheers,
Paolo
 
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