Just a little question...
This thread seems to have evolved into a discussion of how to solve the problems posed by using a 6C45 as the input valve of a power amplifier. Is there a particular reason that you have chosen this valve rather than any other? Do you want to share the whole power amplifier diagram?
This thread seems to have evolved into a discussion of how to solve the problems posed by using a 6C45 as the input valve of a power amplifier. Is there a particular reason that you have chosen this valve rather than any other? Do you want to share the whole power amplifier diagram?
Well, I have heard a lot of good words about 6C45 and I wanted to try them, so I bought a couple.
But I haven't tried them yet.
Other tubes? I have 6922, ECC82, 6H30.
Sorry, but I haven't got the whole schematic in a proper format to publish here, just on paper.
And the current design is just preliminary, a lot of changes have to be done during the experimenting.
In fact I haven't tried none of my current drawings for this amplifier.
But the design I have now use 6C45 as the input tube, 12BH7 is used as a differentialpair phase splitter and KT88 is used as output tubes(ultra-linear).
But I haven't tried them yet.
Other tubes? I have 6922, ECC82, 6H30.
Sorry, but I haven't got the whole schematic in a proper format to publish here, just on paper.
And the current design is just preliminary, a lot of changes have to be done during the experimenting.
In fact I haven't tried none of my current drawings for this amplifier.
But the design I have now use 6C45 as the input tube, 12BH7 is used as a differentialpair phase splitter and KT88 is used as output tubes(ultra-linear).
alternatives
Hi Bas ,
Sorry to confuse the thread . A possibly good candidate for driving an 813 would be the 6EM7 or it's cheap series string equivalents , 10EM7 , 13EM7 and 15EM7 . This has a high mu (66) and low mu (5-6) 750r Ra beefy section all in one bottle . This may possibly make a very simple way of driving an 813 is the sections are cascaded . As for Fatbottle , well....rumour has it he's hanging around this forum now .
316a
Hi Bas ,
Sorry to confuse the thread . A possibly good candidate for driving an 813 would be the 6EM7 or it's cheap series string equivalents , 10EM7 , 13EM7 and 15EM7 . This has a high mu (66) and low mu (5-6) 750r Ra beefy section all in one bottle . This may possibly make a very simple way of driving an 813 is the sections are cascaded . As for Fatbottle , well....rumour has it he's hanging around this forum now .
316a
Fatbottle is that you? ;-)
The 6EM7 looks like a real good candidate..I believe Vinnie at the AA has posted something like that has he not?
O well it it still such a long time away... that 813..Who knows I might run into a couple of those tubes you mentioned.
I'll stop hi-jacking this guy's thread..I was just curious why the 7N7 was an ideal tube. You know how us amateurs are like when some tube is touted as ideal or good..price of the 7n7 has probably gone up $1 as we speak..
Cheers,
Bas
The 6EM7 looks like a real good candidate..I believe Vinnie at the AA has posted something like that has he not?
O well it it still such a long time away... that 813..Who knows I might run into a couple of those tubes you mentioned.
I'll stop hi-jacking this guy's thread..I was just curious why the 7N7 was an ideal tube. You know how us amateurs are like when some tube is touted as ideal or good..price of the 7n7 has probably gone up $1 as we speak..
Cheers,
Bas
Re: alternatives
If you are going to drive your 813s directly from a CD player, whilst the *EM7 series would work well, you might have too much gain.
316A is on to a good thing with these dissimilar triodes. I have tested certain types for distortion and early indications are that they look good.
You could look for example at 6EW7/10EW7/15EW7. These offer a gain of 20 from one section and 6 from the low ra section. You could easily drive an 813 very nicely from the anode of this beefy section. With simple resistance loading, the two stages would give you A of about 70, which would be just about perfect for driving 813s from a CD player, assuming that you are running the 813s at my favoured spot: 850V and 100mA = c. -75V bias.
7N7
316a said:
If you are going to drive your 813s directly from a CD player, whilst the *EM7 series would work well, you might have too much gain.
316A is on to a good thing with these dissimilar triodes. I have tested certain types for distortion and early indications are that they look good.
You could look for example at 6EW7/10EW7/15EW7. These offer a gain of 20 from one section and 6 from the low ra section. You could easily drive an 813 very nicely from the anode of this beefy section. With simple resistance loading, the two stages would give you A of about 70, which would be just about perfect for driving 813s from a CD player, assuming that you are running the 813s at my favoured spot: 850V and 100mA = c. -75V bias.
7N7
watch out !
...they've heard of the 7N7 in Hong Kong . I sold 50 loctal sockets to a Chinese lady there who was using 7N7 in a commercial amplifier . I only asked her what she was using them for as for a split second I could nearly smell 3a/167m . Soon over there 7N7 will be as popular as special fried rice . Get them while you still can . 14N7's are the way to go though : $2 each on Ebay
ps You know those famous metal based Sylvania 6SN7WGT's ? Well the Sylvania tall-bottle 7N7 is identical in every way , apart from the basing and price of course !
316a
...they've heard of the 7N7 in Hong Kong . I sold 50 loctal sockets to a Chinese lady there who was using 7N7 in a commercial amplifier . I only asked her what she was using them for as for a split second I could nearly smell 3a/167m . Soon over there 7N7 will be as popular as special fried rice . Get them while you still can . 14N7's are the way to go though : $2 each on Ebay
ps You know those famous metal based Sylvania 6SN7WGT's ? Well the Sylvania tall-bottle 7N7 is identical in every way , apart from the basing and price of course !
316a
DISSIMILAR TRIODES.
Hi,
Just for the record,I used a pair of 6EM7s to drive a PP 211 dome years ago.
Worked fine the 211 an should be fine for 813 too.
Not all of them are really cheap but if you don't stick to the 6.3V heaters then a whole host of cheap possiblities open up.
Guess they would find out about the 7N7 sooner or later...
Cheers,
Hi,
Just for the record,I used a pair of 6EM7s to drive a PP 211 dome years ago.
Worked fine the 211 an should be fine for 813 too.
Not all of them are really cheap but if you don't stick to the 6.3V heaters then a whole host of cheap possiblities open up.
Guess they would find out about the 7N7 sooner or later...
Cheers,
Hi,
Well, nobody really answered this. A friend runs the 6S45PE in the "Euridice" and he perfers as much current though the Valve as he can get. He also tends to prefer a sound charateristic that I personally find overly bright.
I personally must side with Ciro Marzio who preferred the WE417A with less current and more anode voltage sonically. Having played with WE417A, 437A, 6S45PE,c triode wired high Gm Pentodes and 6922 and derivates I consistently find that I prefer lower current, higher anode voltage operating condistions, they tend to give a more relaxed, composed and insightfull sound.
What is the upshot of this? Try both the JC Morrison/Dr. Arthur Loesch doctrine of "Hot and Low" and the Ciro Marzio/Kondo/Kuei Yang Wang doctrine of "cold and high", especially when combined with underheating the Valve at the tollerance limit.
Both doctrines give very different sonics from the same valve - decide which you like.
Sayonara
Well, nobody really answered this. A friend runs the 6S45PE in the "Euridice" and he perfers as much current though the Valve as he can get. He also tends to prefer a sound charateristic that I personally find overly bright.
I personally must side with Ciro Marzio who preferred the WE417A with less current and more anode voltage sonically. Having played with WE417A, 437A, 6S45PE,c triode wired high Gm Pentodes and 6922 and derivates I consistently find that I prefer lower current, higher anode voltage operating condistions, they tend to give a more relaxed, composed and insightfull sound.
What is the upshot of this? Try both the JC Morrison/Dr. Arthur Loesch doctrine of "Hot and Low" and the Ciro Marzio/Kondo/Kuei Yang Wang doctrine of "cold and high", especially when combined with underheating the Valve at the tollerance limit.
Both doctrines give very different sonics from the same valve - decide which you like.
Sayonara
MIDDLE OF THE ROAD.
Hi,
Well I'm quite aware of what you can do with a valve to change it's sonic footprint,I find striving for a romantic, lush sound is very much a matter of taste.
I do agree however that a predominantly even order harmonic distortion picture is more pleasing to the ear,it is still just that...distortion.
If one were to strive for an as neutral and faithful to the source as possible equipment I suppose some people may still object?
Cheers,
Hi,
Well I'm quite aware of what you can do with a valve to change it's sonic footprint,I find striving for a romantic, lush sound is very much a matter of taste.
I do agree however that a predominantly even order harmonic distortion picture is more pleasing to the ear,it is still just that...distortion.
If one were to strive for an as neutral and faithful to the source as possible equipment I suppose some people may still object?
Cheers,
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