Hi there, I'm just wondering what you might use if you were doing this.
Just got the PT in and gathering parts and components for amp project #3, a monoblock line level single instrument amp, probably use a pair of KT88's UL in the output section - preamp stages, eq etc to be determined by experimenting.
I'd like to kick this off as a hi fi amp and see how the 6SN7 tubes work in the preamp.
My question is, if you were planning on the final amp using NOS tubes, which current production 6SN7's would you use for the initial experimentation/design phase? Reason I ask is that I often see that some current production tubes are not thought of as having similar electrical characteristics as their older counterparts. I'd like to work with modern 6SN7's that will have a similar performance to any or most NOS ones that are substituted. I'm probably worrying over nothing and thats probably true. But where I'm certainly no expert on these tubes I'd be interested in comments from those that do have a long term familiarity with them. Plus, if I do something crazy during the experimental phase, I'd rather take out a 15 dollar JJ than a nice old expensive NOS tube.
Which current production cheaper 6SN7 would you use for design with the possibility of trying much older ones later on?
Thanks very much,
Phil
Just got the PT in and gathering parts and components for amp project #3, a monoblock line level single instrument amp, probably use a pair of KT88's UL in the output section - preamp stages, eq etc to be determined by experimenting.
I'd like to kick this off as a hi fi amp and see how the 6SN7 tubes work in the preamp.
My question is, if you were planning on the final amp using NOS tubes, which current production 6SN7's would you use for the initial experimentation/design phase? Reason I ask is that I often see that some current production tubes are not thought of as having similar electrical characteristics as their older counterparts. I'd like to work with modern 6SN7's that will have a similar performance to any or most NOS ones that are substituted. I'm probably worrying over nothing and thats probably true. But where I'm certainly no expert on these tubes I'd be interested in comments from those that do have a long term familiarity with them. Plus, if I do something crazy during the experimental phase, I'd rather take out a 15 dollar JJ than a nice old expensive NOS tube.
Which current production cheaper 6SN7 would you use for design with the possibility of trying much older ones later on?
Thanks very much,
Phil
If the amp will be used continuously in the future it would be better to base it on
current production components. NOS tubes will not be more available.
You _could_ do your experimentation with both NOS and new production trying to
evaluate any differences and seek a circuit design that picks up the best of both types.
current production components. NOS tubes will not be more available.
You _could_ do your experimentation with both NOS and new production trying to
evaluate any differences and seek a circuit design that picks up the best of both types.
6SN7's current production
Thank you Petertub, you make a good point.
And since this is an amp for a line level electric guitar (of sorts, but not exactly) my sonic expectations may be very relaxed as compared to an amp used for low distortion, high resolution music re-production.
To your point, it may be very interesting to have both old and new, and do continuous A/B'ing if not to just answer curiosity on the differences. And who knows, I may come to the conclusion that one or the other is a better fit for the amp and application. That sounds like a very prudent approach. And I am curious.
Is it agreed upon that most of the new current production 6SN7's are similar enough to be mutually compatible in most amps designed with them? I was also trying to see if there was any conflict with particular brands not being "true" 6SN7's.
Thanks Petertub
Phil
Thank you Petertub, you make a good point.
And since this is an amp for a line level electric guitar (of sorts, but not exactly) my sonic expectations may be very relaxed as compared to an amp used for low distortion, high resolution music re-production.
To your point, it may be very interesting to have both old and new, and do continuous A/B'ing if not to just answer curiosity on the differences. And who knows, I may come to the conclusion that one or the other is a better fit for the amp and application. That sounds like a very prudent approach. And I am curious.
Is it agreed upon that most of the new current production 6SN7's are similar enough to be mutually compatible in most amps designed with them? I was also trying to see if there was any conflict with particular brands not being "true" 6SN7's.
Thanks Petertub
Phil
I would go for 6N8S just because they're like $1-2 here.
But the shipping costs might make them less attractive in the other parts of the world 🙁
But the shipping costs might make them less attractive in the other parts of the world 🙁
Welcome!
There is an Instruments & Amps part of the diyAudio forum.
They discuss Guitar Amps.
This is the Tubes / Valves part of the diyAudio forum.
Generally, Hi Fi amps are discussed here.
Generalizations:
Cheap is not Good.
Good is not Cheap.
If you have negative feedback "wrapped" around a tube and its circuit, that can make it harder to hear
differences of different tubes.
Probably one of the greatest sound differences is when the tube is highly overdriven; not when it is at low volumes.
There is an Instruments & Amps part of the diyAudio forum.
They discuss Guitar Amps.
This is the Tubes / Valves part of the diyAudio forum.
Generally, Hi Fi amps are discussed here.
Generalizations:
Cheap is not Good.
Good is not Cheap.
If you have negative feedback "wrapped" around a tube and its circuit, that can make it harder to hear
differences of different tubes.
Probably one of the greatest sound differences is when the tube is highly overdriven; not when it is at low volumes.
Last edited:
Thanks 6A3,
This thread is more of a question about tubes for Hi Fi amps but thanks for taking time.
Best,
Phil
This thread is more of a question about tubes for Hi Fi amps but thanks for taking time.
Best,
Phil
If you want cheap SN7’s for experimenting in the states, get the 12SN7. NOS US brands can easily be had for $5. ESRC wasn’t the *only* place you could get them (but was an obvious choice, in the same trip to Skycraft). Save the $17 6V tubes for the final build.
Where? I prefer 12V tubes but I spent like 20$ each on NOS Westinghouse made in Japan (cheapest I found at the time).
Vacuumtubes.net had the 12SN7 and 12SL7 listed for $5 - same price as they were at ESRC (where I got my last batch from).
And they are a legit seller - I just got my 26LW6 batch from there. Prices overall comparable to ESRC.
Thanks. Usually I get tubes through eBay lol
They want 5$ a liece for them but there are a couple of tubes of interest on their cheap list. Shipping will suck from the USA though.
They want 5$ a liece for them but there are a couple of tubes of interest on their cheap list. Shipping will suck from the USA though.
Last edited:
I consider $5 apiece cheap for tubes. When it’s either that or $17-20 for Sovtek/New Sensor.
Can’t believe you didn't know about them - I think I found out about vacuumeubes.net from an old Tubelab George post somewhere.
If shipping sucks, just make sure you buy enough to make it worth your while. That’s what I used to do with everything before “free shipping” from parts express and others was the norm, and sill do most of the time anyway.
Off-voltage tubes are often a much cheaper alternative in generaL. Every time I’ve seen good High power sweep tubes in 6 volt they’re either stupid expensive (ie, just as cheap to get KT120’s) or the stock is dried up.
Can’t believe you didn't know about them - I think I found out about vacuumeubes.net from an old Tubelab George post somewhere.
If shipping sucks, just make sure you buy enough to make it worth your while. That’s what I used to do with everything before “free shipping” from parts express and others was the norm, and sill do most of the time anyway.
Off-voltage tubes are often a much cheaper alternative in generaL. Every time I’ve seen good High power sweep tubes in 6 volt they’re either stupid expensive (ie, just as cheap to get KT120’s) or the stock is dried up.
Yup... I'm finding it hard to find some of the Soviet tubes I used to get cheap. I guess everything goes up LOL and 5$ is cheap considering i"d pay about that for 6N8S if i just needed a couple.
pjd3,
Sorry, I mis-interpreted your post # 1 statement:
. . . "a monoblock line level single instrument amp" . . .
I focused in on "instrument amp".
Sorry, I mis-interpreted your post # 1 statement:
. . . "a monoblock line level single instrument amp" . . .
I focused in on "instrument amp".
I can see how that could be taken as something else.
What's uncanny is that the inputed signal is coming from an electric guitar form factor but with use of an Ebow "electronic bow". You see voltages averaging between 2-3 volts often which is absurdly high for a typical guitar pickup output. Plus, I have a very strong intuition that a very clean signal will be most desirable for this instrument, at least my experimenting with DI's, mic pre's and DAW's tell me this. I do intend on attempting to add distortion stages while experimenting but, if this adds no value to the sonic texture, I'll give it up real quick and just have it as a purely hi fi monoblock. You can always add distortion other ways if needed.
Thanks and best,
Phil
What's uncanny is that the inputed signal is coming from an electric guitar form factor but with use of an Ebow "electronic bow". You see voltages averaging between 2-3 volts often which is absurdly high for a typical guitar pickup output. Plus, I have a very strong intuition that a very clean signal will be most desirable for this instrument, at least my experimenting with DI's, mic pre's and DAW's tell me this. I do intend on attempting to add distortion stages while experimenting but, if this adds no value to the sonic texture, I'll give it up real quick and just have it as a purely hi fi monoblock. You can always add distortion other ways if needed.
Thanks and best,
Phil