Tube Amp Archive

As for 2016 that vintage Jensen got replaced with a Eminence Cannabis Rex hamp-coned speaker. Wery nice improvement in tonal characteristics

Here it is https://tubeamparchive.com/viewtopic.php?t=25657

quote="M Fowler"]haknuts what did you do with the old jr chassis?[/quote]

Just wanted to share how the remains of the Blues Jr was put to use. Had a nicetohave EH Caliber 22 in the drawer. Mounted an aluminium bracket inside the cab ann fastened the Cal to it with welcro-tape. The original Eminence speaker is still onboard. Sounds great. The recabbed dovetail Jr on top.

Great discussion, and I think we have estabelished the facts regarding the PT :-) The biasing of the output tubes of the Jr have been widely discussed, but I have not seen any discussions reg biasing the preamp tubes? My Jr is modded (27K R52) for 70% bias at normal voltages. At 340VDC B+ i still ha...

ToneMerc: Would you agree with me here "...what confuses me is that if you look at how the PT is visualized here, it may seem like the 240VAC config involves more windings than at 230VAC " I would expect that in order to keep the secondary at the rated level, a higher input voltage would require les...

ToneMerc:
Would you agree with me here "...what confuses me is that if you look at how the PT is visualized here, it may seem like the 240VAC config involves more windings than at 230VAC "

Interesting theory Stevem! If I understand you correctly, Your approach is that the primary windings are those between white/black and black. It is my understanding of both map and the terrain that the primary windings are between violet and black. S6 is N/C, S2B is the switch and P4 goes via the fu...

In Norway the AC mains is rated at 230VAC. However this voltage varies depending on your supplier, distance to distr.transformer and net load (+/- 5%) . At home my mains is at the higher end of that scale. B+ then was 340VDC, whilst the schematics expects 329VDC. Obviously this affects the amps perf...

Using my Smartphone I have experienced making double posts.

Am I supposed to be able to delete these?

How?

Delete - sorry

A somewhat sturdier base for the tubes. The ceramic sockets I had could not be used, but I managed to dismantel their steel pipes and attach them to the Jr's stock sockets. Resoldered, cleaned and tightened the sockets once again. They have sign of heat corrosion and I think the heat also has an aff...

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I had to sort out my weapon-collection. Found this case at 75$

Confession: I recently installed a new matched pair of 84's, after tightening up the untrustwourthy sockets. I guess the amp has run just a few hours since then. However, the building of the new cab may have put some stress to the amp. I just discovered one of the tubes were kinda deadish. Retighten...

As it turns out, it is not the speaker that buzzes, it is the amp. Have a separate thread about the problem here: https://tubeamparchive.com/viewtopic.ph ... 782#312782