Yorkville Bloc 80B - replacement speaker?

[definenredefine]

Hello! I'm new here. For my first thread ever -

I recently picked up a Yorkville Bloc 80B because...well, quite honestly, I've been looking for a Bloc 40B like the one I had as a dumb kid. (Dumb because I lent the amp to a friend of a friend, who joined the military without ever returning it. Haven't heard from him since. It's been 20 years.)

Anywho, the amp sounds a little thin and bit distorted. I remember my 40 sounding like I was running distortion so at first I didn't think much of it. However, I also remember my 40 being surprisingly loud and the 80 just...isn't. On a whim I used the headphone jack on the 80 and it sounds SO much better.

So I wanted to know if I'm correct in thinking the speaker is the problem. If so, what's a suitable replacement? I'm limited by the 4 ohm impedance, and also by the fact that it's a little silly to spend more than $100 on a speaker for an amp that was $70.

I read through this thread - Replacement speaker for Traynor Bloc80B - and saw some interesting suggestions. Any others? Anyone from that thread care to weigh in?

Oh and ALSO I've been really interested in 12" speakers for bass lately. What if I replace the 15" in the 80B with a 12"??? </mad scientist>

Long first thread. Sorry!

 

[MtManiac]

I used a Bloc 40B and only that from 1986 to about 2007.

As a result, I have developed a fairly heavy right hand technique from trying to be heard.

I kept the amp around for several years but sometime around 2018-19 I noticed it was distorting. Then, a fuse blew. I replaced the fuse three times, and it kept blowing. I’d thought the speaker was blowing, so I’d bought an Eminence 10” and no, it wasn’t the speaker. I ended up retiring it to the landfill, finally. Which was sad, because I remember my dad bringing it home brand new, and how proud he was to have gotten it for me.

Anyway, I don’t have an answer for any of your questions, sorry. I’m technically inept but had an electronics engineer friend who worked on the Space Shuttle’s Canadarm take a look at my Bloc 40B a few times, and his assessment was basically “she’s shot, mate.” Your symptoms sound similar to what I was experiencing. I think something’s gone in the board itself.

I wouldn’t replace a 15” with a 12” - I’m not sure you’ll be able to mount it reliably inside the cabinet. There’s a sheet of plywood with a speaker sized hole cut into it, so stepping down in size is not going to leave you with anything to attach it to. Aside from that, cabinets are designed for the speaker that they come with, so even if you could securely mount it, it may suck.

Best option IMHO is probably finding another Bloc 80B and see if you can Frankenstein one working one together.

Or buying a new modern combo.

 

[definenredefine]

I miss my Bloc 40B...And that was a tragic story! I'm sorry yours bit the dust.

I figured I could mod the cab to make it work with a 12", but the rest of your point still stands so yeah, probably not a great idea. I hope it's not a problem with the board itself because again, the amp wasn't expensive so I don't want to put too much into it. I figured it would be good for small, coffee house type gigs (even though I'm in a punk band, we sometimes play small bars where I probably wouldn't need my head + cab).

At the same time, it took me so long to find another Bloc combo, so maybe it's worth it to keep it running???

May need to do some experimenting...

 

[MtManiac]

Sincerely, best of luck! They were tanks. I played mine as underpowered as it was with many different drummers and bands, including multiple 6-piece jazz combos, three non-gigging metal bands with aggressive drummers, a country band, several dad rock bands, and many, many jam sessions. My right hand technique suffered as a result, and I really wish now I’d used something more appropriate all those years. The 80B obviously would have delivered a louder experience. As tough as they are, they’re classic Traynor through and through. If you want to try something else out, the Bassmasters from the 90s can often be found pretty cheap, sometimes under the Yorkville brand, and I’m pretty sure I’ve seen a few Bloc 40B and 80B models also under the Yorkville brand.

 

[frankie5string]

Wow, I had a block 80b... As long as the speaker you get works for the dimensions of the box and the power the amp can produce, I don't see a problem with experimenting. However, I do remember spontaneous damage to the preamp (input) could happen to those amps at any time. I've had a few of their input boards changed over the years but that was probably 25 years ago when we had a bunch at our local high-school that were subject to abuse.

Lots of happy high-school memories using those amps, though... with an El Degas bass guitar... ;-)

 

[definenredefine]

@BillMason - I have a GK 800RB and Peavey 400 Bass so I'm set for "giggable" amps...I bought the Yorkville pretty just for nostalgia for my departed Bloc 40B. I did think the 80B would be good for smaller gigs but not until I sort out it's volume issue. I do appreciate the well wishes, though!

@frankie5string - I think that's the challenge. I'm not sure what speaker would work in that box. I was kinda hoping one of the folks here would have a suggestion... Also those old Japanese instruments are awesome. I have a Westone guitar from the early 80s that I love.

 

[definenredefine]

Resurrecting!

On a whim, I pulled the speaker from the amp and ran the wires into an old JBL bookshelf speaker. I ran it at a low volume being mindful of the fact that an old 6" mid-bass won't handle a bass amp as well. It sounded a bit better at low volume than the 15" despite the inherent limitations of the speaker employed.

The other thing I noticed is that the cone on the original 15" does not move. I pressed lightly on the dust cap - no movement. Ditto for the spider. Seems to me the voice coil is seized up, maybe? Can that be fixed or is the speaker toast?

 

[frankie5string]

The other thing I noticed is that the cone on the original 15" does not move. I pressed lightly on the dust cap - no movement. Ditto for the spider. Seems to me the voice coil is seized up, maybe? Can that be fixed or is the speaker toast?

If that's the case, then yes, the speaker is toast but likely could be re-coned if you wanted to. It might be easier to find a replacement speaker but you could call Yorkville/Traynor and see if they have any re-coning options for that speaker. I can't remember what make/model the speaker was but back then they used a few different suppliers after opening up a bunch of them over the years, they had a wide range of "white label" speakers with no names on them.

 

[byacey]

I used a Bloc 40B and only that from 1986 to about 2007.

As a result, I have developed a fairly heavy right hand technique from trying to be heard.

I kept the amp around for several years but sometime around 2018-19 I noticed it was distorting. Then, a fuse blew. I replaced the fuse three times, and it kept blowing. I’d thought the speaker was blowing, so I’d bought an Eminence 10” and no, it wasn’t the speaker. I ended up retiring it to the landfill, finally. Which was sad, because I remember my dad bringing it home brand new, and how proud he was to have gotten it for me.

Anyway, I don’t have an answer for any of your questions, sorry. I’m technically inept but had an electronics engineer friend who worked on the Space Shuttle’s Canadarm take a look at my Bloc 40B a few times, and his assessment was basically “she’s shot, mate.” Your symptoms sound similar to what I was experiencing. I think something’s gone in the board itself.

That's a shame. These were a simple amp and could have been easily repaired by someone who knows what they were doing.

 

[byacey]

If that's the case, then yes, the speaker is toast but likely could be re-coned if you wanted to. It might be easier to find a replacement speaker but you could call Yorkville/Traynor and see if they have any re-coning options for that speaker. I can't remember what make/model the speaker was but back then they used a few different suppliers after opening up a bunch of them over the years, they had a wide range of "white label" speakers with no names on them.

Depending what happened to it, it could possibly be reconed. If the magnet is shifted, pitch it.

 

[MtManiac]

That's a shame. These were a simple amp and could have been easily repaired by someone who knows what they were doing.

Yeah, the electronics engineer who was working on it was a drummer, but he was also a retired military electronics engineer who managed quality control on the CANADARM, so maybe not everyone. Having said that, I didn’t want him wasting much of his time for what’s ultimately an underpowered home practice amp.

 

[agedhorse]

That's a shame. These were a simple amp and could have been easily repaired by someone who knows what they were doing.

Agreed, comes back to my seemingly constant comments about needing quailed service techs and not hacks.

Depending what happened to it, it could possibly be reconed. If the magnet is shifted, pitch it.

Agreed, if the magnet has shifted or the pole piece broke free from the back plate, it’s not repairable.

 

[definenredefine]

If that's the case, then yes, the speaker is toast but likely could be re-coned if you wanted to. It might be easier to find a replacement speaker but you could call Yorkville/Traynor and see if they have any re-coning options for that speaker. I can't remember what make/model the speaker was but back then they used a few different suppliers after opening up a bunch of them over the years, they had a wide range of "white label" speakers with no names on them.

Agreed, if the magnet has shifted or the pole piece broke free from the back plate, it’s not repairable.

I don't think that's what happened. Everything looks (to my amateur eye) to be more or less where it's supposed to be. Never the less, I think reconing isn't worth the cost/trouble. I think it's better to replace the speaker with a new unit that'll hopefully be more efficient, etc. Of course there's the whole "will it work in a cabinet with these dimensions/port/etc" and yeah I just don't know. Maybe I can ask the folks at Eminence or Yorkville?

 

[byacey]

You won't know what is going on until you cut the old cone out and examine it. Likely you won't see the damage on the outside, or at least removing the dust cap to see what is happening with the coil former and pole piece.

Edit: Many of the Yorkville product used really lightweight (economy) Eminence drivers that probably aren't worth the cost of a recone. Your amp could probably benefit from a more robust replacement.

 

[definenredefine]

You won't know what is going on until you cut the old cone out and examine it. Likely you won't see the damage on the outside, or at least removing the dust cap to see what is happening with the coil former and pole piece.

Edit: Many of the Yorkville product used really lightweight (economy) Eminence drivers that probably aren't worth the cost of a recone. Your amp could probably benefit from a more robust replacement.

I think that's the direction I'm headed. It's kinda silly to drop in a speaker that's worth more than the amp, but meh, I really wanna hear what this thing sounds like at its fullest potential. I'd like to drop in a Hartke Hydrive but those replacements are cost prohibitive (and they're all 8 ohms, and I think the original is 4 ohms.) There's a celestion 4 ohm 15" that can be had for less than $100 new but they're on backorder. So I'll probably try to find an Eminence that's close to original driver spec.

 

[definenredefine]

Also playing through the old driver sounds thin and kinda distorted. Might be cool for recording...

 

[agedhorse]

You can’t see the damage we suggested, it’s invisible to the naked eye. Your amateur eye isn’t any better than a naked eye either.

 

[definenredefine]

You can’t see the damage we suggested, it’s invisible to the naked eye. Your amateur eye isn’t any better than a naked eye either.

I think I misunderstood and/or misread your comment about the magnet shifting.

 

[frankie5string]

I think that's the direction I'm headed. It's kinda silly to drop in a speaker that's worth more than the amp, but meh, I really wanna hear what this thing sounds like at its fullest potential. I'd like to drop in a Hartke Hydrive but those replacements are cost prohibitive (and they're all 8 ohms, and I think the original is 4 ohms.) There's a celestion 4 ohm 15" that can be had for less than $100 new but they're on backorder. So I'll probably try to find an Eminence that's close to original driver spec.

If the controls work and it's not blowing fuses, I think it's still worth it to get a replacement driver. They're still solid amps with good tone controls and were of a good size. I'm a bit shocked that they're turning up for over $200 used in some parts of the world.

 

[definenredefine]

If the controls work and it's not blowing fuses, I think it's still worth it to get a replacement driver. They're still solid amps with good tone controls and were of a good size. I'm a bit shocked that they're turning up for over $200 used in some parts of the world.

They are??? That's kinda nuts!!! I mean good, solid amps for sure but that seems a bit much.

Anyway yeah, I was pleasantly surprised how much the sound improved even just running it at low volume through the JBL bookshelf speaker.