Tube Upgrade For Ampeg PF-50T?

[Jefenator]

I got one of these bad boys on the way now and I'd like to hear your experiences / opinions: what pre or power tubes have you tried in your Ampeg PF-50T and what kind of change did they make in relation to the stock tubes? (Of particular interest to me would be new, readily available tubes - not looking to go all the way down that vintage/NOS rabbit hole with this particular unit...)

I did come across one post on this a while back but it now seems thoroughly lost in the haystack - seems to me like a topic worthy of its own thread. Thanks in advance!

 

[JimmyM]

I've tried JJ and Tung Sol pre tubes in V1. The Tung Sols were slightly brighter and the JJ's sound the same as the stockers, which are Rubys. I just left the Rubys in it.

 

[justbass57]

I've tried JJ and Tung Sol pre tubes in V1. The Tung Sols were slightly brighter and the JJ's sound the same as the stockers, which are Rubys. I just left the Rubys in it.

The stock tubes sound pretty good, and I haven't read anything better out there (I already did a search on the net)
B.

 

[CryingBass]

Unless you hate the sound of the stock tubes ( unlikely ), then spending the $$ on replacements might not yield the incremental enjoyment you are looking-for. And almost for-sure, the audience ( if any ) will never notice.

 

[Jefenator]

I've tried JJ and Tung Sol pre tubes in V1. The Tung Sols were slightly brighter and the JJ's sound the same as the stockers, which are Rubys. I just left the Rubys in it.

Thanks for the replies, guys! I've had good luck with Rubys in the past - I'll go ahead and stick with that for now.

Unless you hate the sound of the stock tubes ( unlikely ), then spending the $$ on replacements might not yield the incremental enjoyment you are looking-for. And almost for-sure, the audience ( if any ) will never notice.

How did you know I was going to be using this amp mostly on Jazz gigs?

 

[BassmanPaul]

As you have yet to receive your new amp, why not just try it as it is? In our line of work tube brands don’t make all that much difference. There might be a tiny difference but that could well be real or imagined. You’ll spent a lot of cash reaping little reward.

 

[beans-on-toast]

Something that you might want to experiment with is the power tube bias. You can set it a little hotter or cooler to your taste. They discuss this in the manual which you can find at Ampeg.

There are differences with tubes, it can be subtle. When you are chasing tone for recording, subtle is important.

In general, I like Mullard and Tung-Sol here: [Invalid or Expired Link Removed]

I hear good things about Telefunken but yikes! $44 Link Removed

Check out tubesandmore: Invalid Link Removed
A lot to choose from.

You don't have to get into this right away. Get to know the amp. It never hurts to have a spare set of tubes. The power tubes have to be matched. All the places listed do a good job at that.

 

[LVannerson]

I know this is an old thread but thought I would give it a try. Has anybody tried replacing the 6L6s with 6550s? I believe you can do that and the self biasing option is right there. Just a thought as the old SVTs used 6550s. Thanks

 

[Wasnex]

I know this is an old thread but thought I would give it a try. Has anybody tried replacing the 6L6s with 6550s? I believe you can do that and the self biasing option is right there. Just a thought as the old SVTs used 6550s. Thanks

Probably not a good idea. 6L6GC is rated for 0.9A heater current and 6550 is rated for 1.6A. You might burn out you power transformer.

If you want tube with higher dissipation rating, Tung Sol offers a 7581A and 7027A. Heater current is 0.9A just like a 6L6GC, but the plate dissipation is 5W higher at 35W. There are rumored to be the same guts in different bottles, and the 7581A is less expensive.

Using a bigger tube may change the sound a bit, but your unlikely to get more power. If you want more power, get a V4B.

 

[beans-on-toast]

I know this is an old thread but thought I would give it a try. Has anybody tried replacing the 6L6s with 6550s? I believe you can do that and the self biasing option is right there. Just a thought as the old SVTs used 6550s. Thanks

This came up, the amp’s designer said don’t do it.

 

[BassBeginer64]

So, Sovtek or Tungsol for upgrade replacement for 6L6 GC, I lean towards the Tungsols from past use, thoughts........

 

[JimmyM]

So, Sovtek or Tungsol for upgrade replacement for 6L6 GC, I lean towards the Tungsols from past use, thoughts........

Ya, I might agree with you. Me, I still use the stock Rubys.

 

[BassBeginer64]

Went with a set of TAD 6L6GCM-STR, WOW! what difference from Sovteks that were in it, went with a TAD 025 in the v1, Tungsol's in the v2 12ax7 and v3 12au7.
I have it hooked up to barefaced bb3 , wow wow wow !

 

[mike buzzetti]

In a guitar amp Tubes actually make BIG differences but this is a distorted high gain mode ! more sustain etc. in bass amps we normally do not run tubes in this area that much , If you want to then you might notice a bigger difference, if not go with what ya got.

 

[rodl2005]

Went with a set of TAD 6L6GCM-STR, WOW! what difference from Sovteks that were in it, went with a TAD 025 in the v1, Tungsol's in the v2 12ax7 and v3 12au7.
I have it hooked up to barefaced bb3 , wow wow wow !

Do you think it's the power tubes or the pre amp tubes that made the most difference?

Or..... both?

 

[Wasnex]

Went with a set of TAD 6L6GCM-STR, WOW! what difference from Sovteks that were in it, went with a TAD 025 in the v1, Tungsol's in the v2 12ax7 and v3 12au7.
I have it hooked up to barefaced bb3 , wow wow wow !

Great! We understand you really like it, but we don't have any idea why. So can you provide some objective nuance on how each tube model modified the tone and performance? What stands out? What qualities changed, and how?

For example, in my experience current production Tung Sol 12AX7 tends to bring out the high mids and sound hard and punchy. IMHO, it's a pretty in your face tube. I understand why people love it, but it tends to take the tone and feel of most bass amps in sort of the opposite direction of what I usually want.

 

[BassBeginer64]

Best way I can descibe it when I play is cleaner and fuller - depth to my ear, depending on which bass I am playing using my 51 tele with sting pickup and TI flats , playing with the gain some more on the overdrive, i want to play on my PF-115HE vs the BB3 cab, basiclly every thing sounds great off the BB3

 

[BassBeginer64]

Now I understand why the amp sounds better, the power tubes in it were Sovtek 5881wxt 23 watt vs TAD6L6gcm-str 30watt are now in it.

 

[beans-on-toast]

Now I understand why the amp sounds better, the power tubes in it were Sovtek 5881wxt 23 watt vs TAD6L6gcm-str 30watt are now in it.

A 5881 is not a 6L6GT. It has a lower plate voltage spec. In some amps a 5881 can be substituted for a 6L6GC, in others it can’t. The 5881’s might have distorted at a lower volume in your amp. Good for guitar.

Since your amp was designed to use a 6L6GC power tube, it’s best to stick with that. Make sure that you properly set the bias with the change of power tubes. Follow the instructions in the manual.

Enjoy your amp.

 

[BassBeginer64]

3 years later, tung sols in the preamp, 7581A power tubes biased at 65%, lil head bloomed with these tubes, it's taken a few years but I think I have the RCA short greys I been wanting to try out in this head, waiting on a RCA 12AU7 to come in. I don't know why this head seems to work better with 212's than a single 12.