GlamBass74

@Phil Starr - i cant wait to see it!

I've been checking daily 😅

The hole that the transistor pokes through...

Fill it up so it radiates heat to the sink? 

Indeed. Thank you.

My BMW bike uses it beneath the CDI unit, so fortunately I have some.

COVID came to play today so I'm not going to be working on the amp for a few days ☹️

Thank you.

I had ordered outputs transistors and resistors

I have also ordered the transistor in question. 

Appreciate your help 👍

The item in question seems to be an MPSA13

Superb. Thank you.

Stuff to look at.

I powered it up this evening and found it's a transistor producing the smoke.

It lives in a hole in the heatsink near one of the power transistors. I've taken it out.... It's in the second pic. Near the third from the left transistor covered in white goo.

I've repaired the headphone socket. The contacts now make when the 1/4 plug is removed.

Now to look at the schematic and see what this burnt part should be.

Cheers! 

LONG POST WARNING

Hi All

Bought an Ampeg B100R yesterday for a very, very low price

Was listed as spares or repair, so in my mind i was going to rip out the amp and fit a speakon on the back like I did with my BA115HP (again bought as spares or repair a few years ago)

Got it home and marvelled at the condition for the cost of approx 4 beers and then decided its a bad move to just ditch the amp section

Symptoms...

Power on - no power. Dead as a doornail

Opened up amp and the 1.5A slow blow was pooped. Checked with a multimeter. No continuity - Ooooo result, but why???

New fuse, switched on... hummed a lot and it released a little bit of the magic smoke after around 10 seconds  bummer. Looked like it came from around the transistors, but cant be sure. Will investigate later. Fuse didn't pop and it still fires up even after losing the smoke.....

So..... I've now removed the amp completely and am thinking it might be fun to work through it

First things first.... Light bulb tester.... Should I consider putting one together? I am thinking of teeing a bulb holder into an IEM cable. I'm thinking i'd need a 100+ watt bulb to make it work properly. Are these rare items these days?

Grille is held in with velcro pads. Persuaded out with a flat blade screwdriver and hope. Will staple a fabric tab on the frame to enable me to pull it out easier next time (next time????)

Speaker is fine - tested with another amp and works well. Apart from the dust it looks mint. Code is 86-118-14. 4 ohm. Looks very Eminence..ish

My initial prodding with a multimeter seem to indicate the there's a few 0.33 ohm 5w resistors that aren't showing anything like their correct values. 

The transistors 2 x TIP142 and 2 x TIP147 seem to show the same readings per "pair". Will remove them later and test them individually

I've purchased some new transistors, some resistors (£6 so far) and i've downloaded the circuit diagram for the amp

I have a multimeter, a yoghurt pot half full of common sense and a desire not too end my life too early. 

If anyone would like to chip in, then please feel free. 

If the response is send it to a professional then please save your typing. I can't warrant spending too much on it. My time is my own and learning is good.  If it takes me a few months, but I learn from doing it, then i'll be a happy bunny. If it takes months and it does my head in to the point where I launch it across the garage, then the speakon socket will be installed in the cab and the amp module thrust into the bin in disgust 😁

I'll add to this thread as I discover/damage stuff

Jon

A sub you say???? oh..... how very timely

Yes please!

Still my fave driver.... Can't believe theyre discontinuing them ☹️

I'm currently contemplating building a "modular" setup of dinky 1 x 10 cabs loaded with Beyma 10CMV2 drivers (thanks @fleabag)

1 for home/rehearsal - 8 ohm

2 for small pub - 4 ohm

3 in a column with a strap round them for a bigger pub - 2.66 ohm

4 for outdoor in conventional 4 x 10 format - 2 ohm

30L enclosures made from 12mm ply. Toolstation manrose pipe porting and Rustin's step paint finish (see? - i'm cheap!). May even skip a tweeter on the first to see how it sounds. 

This way I can take what I need. 

I've sized the design to slip into a cheap Thomann cajon case. Bit of protection and the ability to carry like a rucksack....

3 can be cut from an 8 x 4 sheet

My partner is overjoyed at the prospect of more cabs in the spare room 

I'm such a nerd.....

I'd look ridiculous playing mine - i'm not a small chap (but then again, this is a man that rode a Honda 90 from Norwich to John O Groats and back so anything goes really)

I think it'll be a home playing only bass 😁

Might even lush it up with a new set of strings..... 'bout time

I cleaned mine up last night and tried it - SUCCESS!

What a strange tone. Very "thunky" - really quite nice

A bit crackly, but nothing I cant fix

@neepheid Hurrah! some good vibes!

Yep... 20mm wide copper tape

Good lighting

Scissors

Tea/Coffee/Cocktail

Soldering iron (to remove and replace wiring)

Meter (to test that all strips/cavities/parts have continuity)

Spanner to remove pots & jack socket

Screwdriver

It was a strangely rather enjoyable job

Just checked....My copper tape was £6.99 for 20m. I probably used about 500mm 😁

I don't know the science behind it all, but I really don't care. I did it. It works. I'm happy

I just had a look at that - brilliant! Thank you

Its certainly not something i'd consider using, but I just can't get rid.... Pointless really, but i'm a bit like that 😁

Thank you everyone for your comments. At last I actually know what it is! 👍

Hi All.

Can anyone shed any light on this beast? 

I've had it in my loft for about 30 years.

Any sensible info appreciated! 😁

thanks Bunion - i'm chuffed ☺️

Not the prettiest, but it works a treat!

The bridge had a wire fanned out beneath it that was earthed on the back of a pot

I also put copper tape beneath it as well as the wire

I made a copper tape "wire" to run from the pickup cavity to the control cavity and made sure I had continuity between them

Passed between each cavity and taped in place

I overlapped the tape from the cavities to the backs of the scratch and pot plate so they had continuity when screwed back on

It wasn't super pretty, but it did a good job. 

I wasn't expecting the improvement I got.... It really has transformed the old girl 

I will definitely be gigging the old girl now ☺️

Helloski

I bought a Harley Benton Jazz copy in the Summer of 21 purely out of curiosity. £139???? It's gotta be rubbish hasn't it? Err , no!

Natural finish Vintage Series JB75-MN

Apart from it's sheer heft, I love it. Love the look and love the way it plays

There's one thing that's been bugging me though. Playing... no buzz. hands off strings..... buzz!

I bought some 20mm wide copper tape from Ebay and last night I set about shielding the body (no provision for shielding whatsoever on this from the factory)

About 2 hours to do it all, link all cavities, cover back of plates, test with a meter and stick back together

Now - Perfick!

I know i've not re-invented the wheel, but what a satisfying job to carry out. Even made The Apprentice bareable to watch (where do they find those people????  )

So... Happy Glambass

That's it really.... Bye!

Jon

I 

11 hours ago, lemmywinks said:

 

Do you have a thread for the Basslite 1x10? I love home built micro cabs, could read build threads all day!

Hi.

I didn't plan on one, but I'm only at the winisd stage at present

I will have a think about it. 

I've built 2 easy builds, a mk2 basschat cab and am now finishing a mk3 - they're great designs (stevie and phil are great contributors to this forum and very helpful)

I'm going "solo" on this one. I have the speaker and i'm going to see what I can get from it. 😄

Speaker cabinet building seems to be my "catnip".... i'm addicted! 

I recently bought a BAM200 for rehearsals with a tiny 1x10 basslite loaded cab i'm currently building

My other reason for purchase is to stash it in my gig bag to get me over the line if my main amp (TC BH800) bites the dust

Its silly tiny. 

Its loud for it's size and spec - I wouldn't consider using it to gig with on a regular basis

Not sure of output @ 8 ohms, but I would imagine 150-160 watts maybe?????

It's no frills (power switch, mains in, speaker out 1/4, input, headphones, gain, low, mid, high, volume, DI, ground/lift)

Its nicely put together

The fan is pretty quiet

The eq is very tweakable

My ears hear a fair bit of signal compression as the gain is wound round

For the cost (£117.50 when ordered) I thought it'd be a get out of jail card for future gigs

If you're normally a speakon/speakon lead user, you'll need a jack/speakon lead. 

Easily stashed, easy to use, cheap enough to lay dormant without feeling bad about not using it all the while

Looks crazy sat on top of any "normal" gigging type cab.... Like somebody's left a packet of smokes behind 😁

Cute little beasty

that's brilliant

thank you so much for taking the time to help me out

i'd got a bit peeved about the bass after buying it, but with your diagram I can double check it all

if i ever meet you, I owe you a pint or three

☺️

You sir, are a gent.

Thank you for doing/checking that.

The original seems to show red jumper wires. Would you agree? 

Yeah, but the switch area is grainy and vague. I've tried zooming it