Retube my Marshall 2001 Bass Head.

[jesuskno]

Hello. I need your advice.
Need retube my Marshall 2001 Bass Head I acquired a few months ago.
Last week we take you to review it because I'm going to use in the recording of an album.
What was our surprise. He had some original factory powertubes 6550 General Electric. Others had been changed by kt88 bottle shapes, no marks. Were mixed with each other.
When we first tested these tubes they just had 5-10% of life ... practically dead.
The preamp tubes are a PM that says made ​​in china. I have not found much information on these valves internet but at first glance its construction seems economical.

The Marshall 2001 leads: 8x 6550. 2x ECC83. 3x ECC81

At first he had thought svetlana, but the last run of these with C logo, say they have given problems and some dealers and technicians have withdrawn.

Some local experts and friends have told me that Sovtek was good choice. They are not so expensive and have good response. Although the internet I have read all kinds of opinions.

In the part of the preamp had thought Mullard reissue. I think wearing Mullard factory (or am confused). But I do not know the outcome of this reissue. In general opinions on the Internet seems to be a good product.

You see I'm a bit lost. I would like to get the marshall sound as similar to the sound source. As the crisis is deep around here I would like to re-tube that was too expensive or that life is very short tubes.

I know everyone has their favorite brand, tips, experiences, ideas ... everything is welcome.

thanks friends.

[Mr. Foxen]

Not tried the 6550 specifically, but Shuguang power valves I have used (EL34b and KT88) have been good and very cheap. Trouble with the pre valves though.

[iiipopes]

[url="http://thetubestore.com/6550types.html"]http://thetubestore.com/6550types.html[/url]

[jesuskno]

[quote name='Mr. Foxen' timestamp='1353861069' post='1879062']
Not tried the 6550 specifically, but Shuguang power valves I have used (EL34b and KT88) have been good and very cheap. Trouble with the pre valves though.
[/quote]

Thanks for your advice
At first I will not put Chinese tubes.
In my Mesa Boogie 400 + put new mesa boogie tubes. They are made in China .... say it with excellent quality similar to those manufactured before mesa boogie in russia. But that's not true. My old mesa boogie tubes sounded much better than the new.
So I'll forget China for now.

I think by now my choice is Mullard ri in the preamp. And Sovtek powertubes.

Some technicians and distributors still retain the old stock new svetlana. I am researching to see if I can find an affordable price.

[jesuskno]

[quote name='iiipopes' timestamp='1353876011' post='1879310']
[url="http://thetubestore.com/6550types.html"]http://thetubestore.com/6550types.html[/url]
[/quote]

Would you advise any particular tube?

Thanks!

[Mr. Foxen]

Where they are made has no bearing on their function.

[Big_Stu]

[quote name='jesuskno' timestamp='1353918527' post='1879593']
Would you advise any particular tube?[/quote]

I've heard quite a few pro techs recommend JJ - and they certainly have a lot of valve amp users who agree. My Hiwatt is due a revalve & it's JJs for me, to replace GECs.

Edited November 26, 2012 by Big_Stu

[Mr. Foxen]

[quote name='Big_Stu' timestamp='1353949549' post='1880133']
I've heard quite a few pro techs recommend JJ - and they certainly have a lot of valve amp users who agree. My Hiwatt is due a revalve & it's JJs for me, to replace GECs.
[/quote]

Look up Shuguang GEKT88, I have some, pretty close in construction to the GEC, and according to Chambonino, close in spec.

[Dad3353]

You wouldn't have a higher resolution pic, by any chance, would you..?

[jesuskno]

[quote name='Big_Stu' timestamp='1353949549' post='1880133']
I've heard quite a few pro techs recommend JJ - and they certainly have a lot of valve amp users who agree. My Hiwatt is due a revalve & it's JJs for me, to replace GECs.
[/quote]

Since a short time so far it seems that JJ's quality has deteriorated.
I have musician friends who in their last JJ's retubes, have had a life of only six months.
Some technicians have discouraged me because lately say these tubes give problems and fail a lot.

[Big_Stu]

That doesn't sound too good; I was at my techs a few weeks ago & he was singing their praises. He also mentioned getting some Chinese ones that were dead straight from the box but he didn't give a name.
Might be worth having a word with Watford valves, or see if there was a faulty batch or something. I've never heard of anything like that about JJs.

[jesuskno]

[quote name='Big_Stu' timestamp='1353956170' post='1880267']
That doesn't sound too good; I was at my techs a few weeks ago & he was singing their praises. He also mentioned getting some Chinese ones that were dead straight from the box but he didn't give a name.
Might be worth having a word with Watford valves, or see if there was a faulty batch or something. I've never heard of anything like that about JJs.
[/quote]

In addition to these comments, I also read on the internet people talking about the latest productions of JJ's tubes.
Not tell if it was a specific productions or is widespread.

Edited November 26, 2012 by jesuskno

[jesuskno]

For example: [url="http://www.marshallforum.com/marshall-amps/34807-yet-another-failed-jj-tube-arrrr.html"]http://www.marshallforum.com/marshall-amps/34807-yet-another-failed-jj-tube-arrrr.html[/url]

[iiipopes]

[quote name='jesuskno' timestamp='1353918527' post='1879593']
Would you advise any particular tube?Thanks![/quote]
Unfortunately, it's been about twenty years since I purchased 6550's. About the same time all those years ago (cue the Harrison song) I sold my SVT bass head and had my Marshall 2203 USA market version guitar head rebiased for EL34's.

Contact them and tell them your budget and sound/durability requirements and see what they recommend. Getting eight matched will not be easy, if possible at all, and very expensive. You might have to go with two sets of matched quads and be careful that you distribute them properly on either side of the push-pull circuit.

Edited November 26, 2012 by iiipopes

[jesuskno]

[quote name='iiipopes' timestamp='1353957950' post='1880287']
Unfortunately, it's been about twenty years since I purchased 6550's. About the same time all those years ago (cue the Harrison song) I sold my SVT bass head and had my Marshall 2203 USA market version guitar head rebiased for EL34's.

Contact them and tell them your budget and sound/durability requirements and see what they recommend. Getting eight matched will not be easy, if possible at all, and very expensive. You might have to go with two sets of matched quads and be careful that you distribute them properly on either side of the push-pull circuit.
[/quote]

I appreciate it. Thanks friend.

[Big_Stu]

[quote name='jesuskno' timestamp='1353957575' post='1880285']For example: [url="http://www.marshallforum.com/marshall-amps/34807-yet-another-failed-jj-tube-arrrr.html"]http://www.marshallf...tube-arrrr.html[/url][/quote]

Thanks for the heads-up. Certainly something to seriously consider, Watford Valves, who I think are the ones my tech sources from also say that they test every valve too. I'd like to believe that but I guess the users in your link thought the same of their supplier ......... & also a slight comfort that there's no mention (AFAIK) of KT88s, for what that's worth.

[geddeeee]

JJ Gold 12AX7 are great for the preamp section.

I would use the Svetlana 6550. These are what Marshall supply from the factory in the VBA 400. The 2001 was the forerunner of the VBA, so I would go with them.

I wouldn't bother with any of the 'cryo' valves either. Absolute rubbish!!! As for Watford Valves.... Our guitarist purchased a set from them for his Marshall head. The power valves were faulty and the amp nearly caught fire at a gig. He paid out nearly £300 trying to get the valves, and then get them biased. In the end he took it directly to Marshall. They fixed it, biased it etc. It sounds like it just left the factory. Only cost £170 including parts. Bargain!!!

My advice would be to send it directly to Marshall for a full service. They know what they're doing....

[jesuskno]

Well I think I have decided that I am going to put tubes in my Marshall, but not know the Plate voltage of this amplifier so I can do the biasing.
Anyone know what this amp plate votage?
Thank you.

... and happy new year!!