This old BASSMAN has STILL GOT THE BLUES Rift Midweek Update

Join this channel to get access to perks:
/ @riftamps
PLEASE NOTE: This is not a tech channel, but simply a show-and-tell. It is not designed to give advice and support on vacuum tube amplifiers but to show what I get up to each week in the workshop.
I deliberately keep tech talk to a minimum, or at least to a point where it’s understandable to the casual viewer. There are other channels more suited to that level of detail.
I do not do reviews, either paid or unpaid. My opinions are entirely my own and do not represent those of others.
All comments are welcome but those deemed unhelpful, rude, inappropriate, or unsavoury will be reviewed and possibly censored.
---------------------------------------------------------------------------------------------
Updates
---------------------------------------------------------------------------------------------
EQUIPMENT I USE
Wire Strippers - uk.rs-online.c...
Knipex Snips - uk.rs-online.c...
Oscilloscope - uk.rs-online.c...
Signal Generator - uk.rs-online.c...
Soldering Station - uk.rs-online.c...
Chisel Tips - uk.rs-online.c...

[@martinreid1740]

Looking forward to seeing you restore the Orange OR 120, I've not seen inside one since the seventies. My brother still has his OR 80 2×12 reverb combo, still going strong. Built like a tank using 3/4 marine ply and weighing a ton.

[@David-gx9lh]

Q?- Where do those extra order harmonics on the PR V1a gain stage come from? They're not in the original signal it seems, so are they generated through the valve? PS, hope you liked the coffee! 🙂

[@seanblythe9109]

I wish we could get a months worth of rain in Chicago!

[@frostbyte5214]

05 / month 24/ week 67 / year , dated , with transformers , 606 / co. Abbreviation , Schumacher , next year, next week , 606 Co 7 year , 17 week . 606 7 17 . Raining here to USA east coast . Hurricane coming in to Florida. Stay dry , 😊

[@markcaruana7233]

Hey there. By coincidence I just took in a 72 Bassman 10 with the same Brite switch scope trace that you displayed on the GM Bassman. I am suspecting the brite sw cap. What did you find? Inquiring minds want to know. Thanks... your friendly vintage amp tech from Central New York Mark 🤘🏼😎👍🏼

[@BCEpedals]

??? How much heat is acceptable at the power transformer? I know some get warm but others get WARM!! How much do you typically expect?

[@GazCal]

Been following and watching for a while now. Really great videos, content and explanations.. Great stuff !! 🎸 🔊

[@GazCal]

Curious .. Which circuit type is the Gary Moore '67 Blackface ? AA864 / AA165 / AB165 ? Without getting to "Technical" ..What are the Differences. I notice a few cap changes, but the difference seems to be Normal Channel signal route before/after 3rd gain stage prior to the phase inverter ? How would that affect output ?

[@rfpho1456]

If you ever get the chance it would be interesting to see the harmonics a solid state pre-amp stage does or doesn’t create. I’m assuming it would be much cleaner (and that’s why we love tubes…)

[@MichaelSmith-rn1qw]

On the Bassman, I'm not sure about the ink stamped code on the external part of the chassis, perhaps a final inspection sign-off? The ink stamp on the inside, near the power transformer T201667 indicates the chassis wiring was completed by Tech #20 during the 16th week of 1967. On the largest ceramic disk cap it looks like some of the outside coating where the lead enters the cap is broken off. Perhaps some moisture has gotten inside. I only caught a glimpse of it as you were panning around. I will be interested to see why the bright switch causes the sine wave to go nuts! And yes, that does appear to be a bias balance circuit. On my 1968 Bassman I added a bias trim pot onto the balance pot, reducing the value of the resistor.

[@Mr_CB]

It was very interesting to see your measurements on the preamp on the Princeton. Those nice linear graphs show that the designers did a good job all those years ago.

[@projekct_amk]

Welcome back mate!

[@sharkair2839]

why would a vintage 30 need replacing? it's one of the most popular speaker in that amp. what was the original speaker in that amp? an oxford?

[@RiftAmps]

Completely wrong EQ curve for that circuit

[@pietervanballaer]

@@RiftAmps I agree. Funny: yesterday AskZac put a video out highlighting three 'preferred speakers' in a Deluxe Reverb: a vintage 30, et65 and the Alessandro GA12-SC64... My preference however would be a WGS G12C

[@watkinscopicat]

@@pietervanballaerJensen C12N.

[@sharkair2839]

@@RiftAmps check this out. 20 Pro's Choices For The Best Speaker For Your Deluxe Reverb

[@ali2ndmail]

50s deluxes came with Jensen and sometime in the 60s they switched to Oxfords. The Jensens are often thought to be amongst the best sounding for a deluxe. They have a dip in frequency response between around 200hz and 700hz and slightly more response in the top end than the mid range. The celestion vintage 30s are nothing like that and have a comparatively flatter response. I normally associate a vintage 30 with Marshall amps and cabs.

[@chaosin73]

Boring - would be quite interested how you put a mains plug on.