[a1rocketpilot]

Does anyone know of a place where one may find info on the sound signatures of various tubes? Without spending a boatload of money on different tube amps and tuberolling, how is one supposed to know a good place to start and what different tubes sound like?

 

[Geist]

http://www.audioasylum.com/audio/faq/joes-tubes.html

A good place to start.

 

[Uncle Erik]

There are other factors that affect tube amps besides the tubes themselves. Spend some time familiarizing yourself with various circuit topologies. For example, do you know what an output transformerless (OTL) amp is? The same tube used in an OTL will sound very different in, say, push-pull configuration with an output transformer. Tubes biased to run in class A will give a different sound than class AB or B amps.

And there's more. There are a lot of variables and a lot to learn.

But there is good news. Don't kill yourself over making the "right" choice. There isn't one. In fact, I'd bet you'd be happy listening to or owning dozens of different amps. There are many out there that sound terrific.

Just keep in mind the fact that there's more than one amp that's right for you. Don't buy more than you need. And if you have the means and desire, build one. You'll really begin to understand if you do that.

 

[a1rocketpilot]

You just brought up another good point. I understand the difference between OTL and Transformer output, but what in the world is all the other stuff like SRPP, SRRP, Mu Stage, Mu follower, etc? I've tried looking them up on Google, but to no avail.

Aditya

 

[Carl]

They're ways of joining the amplification device (tubes, FETs, etc) to the rest of the circuit.


There are hundreds of ways this can be achieved, each with different sounding results. My favourite is DHT driver->interstage transformer->DHT output->push-pull output transformer.

 

[Ferbose]

I don't think much generalization can be made.
If I were to buy a tube amp, I would not be concerned with what its topology is or what tubes it can or can't accept.
I would start by understanding its sound signature, output power and noise level.
Every kind of common circuit topology can be made to sound good. Every type of common audio tubes have been used in many great sounding gears. Different tubes of the same type all sound somewhat different. But there is constant debate and confusion about which 12AX7, 12AU7, EL84 etc. sound best. IME NOS tubes don't necessarily sound better, either. What works well in one system does not necessarily translate to another.

 

[Carl]

Well various topologies and tubes often have a "house sound", for lack of a better way to put it, which leads amp designers to favour a certain approach. There are plentiful exceptions to this, but at least it gives a bit of guidance on where to look.

 

[augustwest]

I think you need to get a basic idea as to which tube amp(s) may fit your budget and needs. Based on the tube size and type that the amp you are interested in takes, you can start researching as to what and how much the tube cost, and what they might sound like. Keeping in mind you can read all you want but you will never know exactly what they will sound like until you listen to them.

Factors to consider:
- Cost and availability of the tubes, and the number you will need. Some amps can be very expensive to tube. Often a single tube isn't that expensive, but if you have to buy two, three, or more it can add up. Some tubes regardless of how good they sound (and look) are just plain expensive, like the 300B tubes. So you will need to factor in these practical issues, as well as the sound they produce.

- Some tubes like the 6CG7, are inexpensive to buy but don't offer many tube rolling options. Others like the 12AX7, and the 6SN7, offer many tube rolling choices, and run the gambit of prices from very cheap to very expensive.

Basically the amp(s) you think you will be interested in will dictate the above requirements, and that will likely be a good starting point. Hope this helps some.

- augustwest