Tube rolling....why does it change the sound?

[Silky999 110]

I have a GB Streamliner 900 that I have put some different tubes in. All were sourced off the dreaded eBay and none cost more than £10. 

V1 - some unbranded 5751 8 shot revolver getter???

V2 - Telefunken ECC83 which has a B at the start of the serial number...Berlin???

V3 - Mullard ECC83 made in Blackburn???

I chose the valves as they were cheap and seemed possibly reasonable manufacturers but I know little to nothing about valves. I wanted a lower gain valve in V1. There seemed to be a lot of talk around long and short ladders, getters and all that malarkey.

The amp sounds so different in a good way now, much clearer and less distortion and just tighter sounding. I get that the 5751 is a lower gain valve so hence less grrrr at a higher gain level but why does changing one brand ECC83 to another in V2 and V3 affect the tone? Surely they are much of a muchness but I noticed a real change when I took the standard Ruby out in V2 and put in the Telefunken. Even more pronounced when the Ruby in V3 was swapped for the Mullard.

 

Can someone explain why one ECC83 affects the tone more than another? Is it just a placebo effect?

Edited February 13 by Silky999

[Stub Mandrel 10,321]

I'm not an expert, but valves are almost mechanical devices, slight differences in dimensions could have profound effects on the actual performance.

[Silky999 110]

28 minutes ago, Stub Mandrel said:

I'm not an expert, but valves are almost mechanical devices, slight differences in dimensions could have profound effects on the actual performance.

They’re fascinating little things aren’t they. Being born at the beginning of the 70s, valves were really not a thing I grew with. I must admit I do love their form and function and there’s something very tactile about them. 

[skidder652003 814]

ooo you got me thinking of getting my DHA VT 2 out of the drawer and putting it in front of my Audio unit!

[paul_5 1,440]

35 minutes ago, skidder652003 said:

ooo you got me thinking of getting my DHA VT 2 out of the drawer and putting it in front of my Audio unit!

Why the f*ck is a VT2 in a drawer?!?

[skidder652003 814]

10 minutes ago, paul_5 said:

Why the f*ck is a VT2 in a drawer?!?

No gigging! Just set it up, sounds great, thanks for the reminder!

[Silky999 110]

49 minutes ago, skidder652003 said:

No gigging! Just set it up, sounds great, thanks for the reminder!

Now that looks a great pedal! I assume it’s a valve based preamp?

[Beer of the Bass 325]

I haven't tested in any objective way, but from the guitar and bass amps I've tried different preamp tubes in (of the same type), it seems like the amount of difference is very dependent on the amp circuit and tube position. In the cases I do feel there's a difference, it's a subtle one. And there probably is a dollop of conformation bias going on too, which makes it even trickier to be sure about.

[Happy Jack 4,753]

5 hours ago, Silky999 said:

Can someone explain why one ECC83 affects the tone more than another? Is it just a placebo effect?

Valves don't last for ever, and you're buying vintage (i.e. old) valves from different manufacturers in different countries. They have had wildly different histories, so they sound different.

If you buy two vintage Fender Precisions they will both sound like a Precision (just as your two ECC83s sound like preamp valves) but they're unlikely to be identical or to sound identical.

 

[Aliwobble 108]

My take on this is that we are moving electricity around from the pickups to the speakers. I guess subtle differences in tube design (e.g. a slightly better quality of metal) will alter the flow of electricity, maybe add a little distortion etc. Sometimes it sounds better, sometimes worse.

[agedhorse 324]

On 13/02/2021 at 12:30, Beer of the Bass said:

I haven't tested in any objective way, but from the guitar and bass amps I've tried different preamp tubes in (of the same type), it seems like the amount of difference is very dependent on the amp circuit and tube position. In the cases I do feel there's a difference, it's a subtle one. And there probably is a dollop of conformation bias going on too, which makes it even trickier to be sure about.

From my experience designing amps, this is generally the most accurate description of what's really going on. And to add... conformation bias is very much a real thing that can be a frustrating source of "non-difference".

[Alec 14]

On 19/02/2021 at 23:31, agedhorse said:

Confirmation bias is very much a real thing that can be a frustrating source of "non-difference".

This - more than you could possibly imagine!

[Chienmortbb 687]

Does the amount of feedback in a stage make a difference?

[JPJ 96]

I recently commented on a thread on a Facebook SWR group about my preference for a 5751 valve in place of a 12AX7 and one of the replies said the 5751 had a gain factor of 70 versus 100 of the 12AX7. 

[Silky999 110]

Yeah the 5751 is about 70 gain opposed to the 100 or so of a 12AX7. With it in V1, I can crank the gain higher before going into overdrive which I prefer.

[agedhorse 324]

The "gain factor" of a tube does not necessarily translate into circuit gain. It depends very much on the circuit itself. There are circuits where a tube with "higher gain" will result in a circuit performing with LOWER gain. It really does depend on the circuit the tube is used in.

Forgive my use of the word tube in place of valve...

[Jus Lukin 3,150]

1 hour ago, agedhorse said:

Forgive my use of the word tube in place of valve...

I'll ask Ped to add it to the swear filter! 😄