Dynacord Bass King, speaker impedance?

[NoiseNinja]

I have just purchased an old but just recently renovated Dynacord Bass King, all tube amp, from '63/'64.

I also bought a 8 Ohm 115 cabinet for it.

But now I am in doubt, cause it seems like the impedance speaker outputs are rated 16 Ohm.

But would that only be the case if you plug in 2 x 8 ohms speakers, one in each speaker output?

I found this piece of info on specifications:

Ausgänge (Outputs): Lautsprecher (Loudspeakers):
2 x 16 Ohm (parallelgeschaltet (connected in parallel))
oder (or) 1 x 8 Ohm

From this piece of information it seems like I was right in buying a single 8 Ohm cab for it.

But just want to be sure.

Also read somewhere that it should have some sort of internal way of adjusting the impedance of the speaker output under the chassis, but not sure how that works or how easy it would be to adjust it?

Anyway I guess there would be no need if my assumption of it being fit for 1 X 8 Ohm cabinet is right.

Also hypothetically, saying I was to plug an 8 Ohm cab into a tube amp rated for 16 Ohm, what would the consequences be?

 

[Stumbo]

I have just purchased an old but just recently renovated Dynacord Bass King, all tube amp, from '63/'64.

I also bought a 8 Ohm 115 cabinet for it.

But now I am in doubt, cause it seems like the impedance speaker outputs are rated 16 Ohm.

But would that only be the case if you plug in 2 x 8 ohms speakers, one in each speaker output?

I found this piece of info on specifications:

Ausgänge (Outputs): Lautsprecher (Loudspeakers):
2 x 16 Ohm (parallelgeschaltet (connected in parallel))
oder (or) 1 x 8 Ohm

From this piece of information it seems like I was right in buying a single 8 Ohm cab for it.

But just want to be sure.

Also read somewhere that it should have some sort of internal way of adjusting the impedance of the speaker output under the chassis, but not sure how that works or how easy it would be to adjust it?

Anyway I guess there would be no need if my assumption of it being fit for 1 X 8 Ohm cabinet is right.

Also hypothetically, saying I was to plug an 8 Ohm cab into a tube amp rated for 16 Ohm, what would the consequences be?

Two 8 ohm speakers in parallel give the amp 4 ohms. Ohms in parallel are not additive.Your amp can handle two 16 ohm cabs or one 8 ohm cab, Your 8 ohm 1x15 8 ohm will be fine.

 

[Martin Beer]

Looking at the schematic, it appears the Bass King has 4, 8 and 16 ohm taps on the output transformer, but in the stock configuration only the 16 ohm tap is connected to the output sockets.
Invalid Link Removed

What I don't know is whether some were supplied with the 8 ohm tap connected as an option, which might be what the "or" in the specifications suggests. It's also possible that since the amp is 50 years old and will have been worked on, the connections might not be as they were originally. It would be a very quick job for a tech to check the connections and hook up the 8 ohm tap to one of the sockets. There will be a row of solder tags on the output transformer, and it's just a matter of identifying these and wiring the right one to the output socket - I did this to add a 4-ohm output to a Bass King T I used to own.
If you do run an 8 ohm cab on a 16 ohm output, it's not likely to do anything catastrophic, but it may be a little harder on the valves and you may not achieve the full power the amp is rated at.

 

[bass wood]

Looking at the schematic, it appears the Bass King has 4, 8 and 16 ohm taps on the output transformer, but in the stock configuration only the 16 ohm tap is connected to the output sockets.
http://www.peel.dk/Dynacord/pdf/Bassking (128-102) (Rev. 1964).pdf

What I don't know is whether some were supplied with the 8 ohm tap connected as an option, which might be what the "or" in the specifications suggests. It's also possible that since the amp is 50 years old and will have been worked on, the connections might not be as they were originally. It would be a very quick job for a tech to check the connections and hook up the 8 ohm tap to one of the sockets. There will be a row of solder tags on the output transformer, and it's just a matter of identifying these and wiring the right one to the output socket - I did this to add a 4-ohm output to a Bass King T I used to own.
If you do run an 8 ohm cab on a 16 ohm output, it's not likely to do anything catastrophic, but it may be a little harder on the valves and you may not achieve the full power the amp is rated at.

Hi Martin,
Could you please tell me, if it is possible to connect two 8 ohm speakers at the same time, to each of the 8 ohm outputs of the Bass King T.
The users manual suggests 16 ohms cabs to pair when using both of the 8 ohm outputs... They are wired paralell I guess, but it's not entirely clear for me...

 

[bass wood]

Hi Martin,
Could you please tell me, if it is possible to connect two 8 ohm speakers at the same time, to each of the 8 ohm outputs of the Bass King T.
The users manual suggests 16 ohms cabs to pair when using both of the 8 ohm outputs... They are wired paralell I guess, but it's not entirely clear for me...

 

[bass wood]

Just checked the schematics, and I guess, in case I would like to keep the possibility of using one 8 ohm cabinet at times, and using 2 8 ohms cabs at other occasions, I will have to solder the 16 ohms output to the 8 ohm tap on the output transformer, and have to move the wires of the paralell 8 ohm outputs to the empty 4 ohm tap.

 

[agedhorse]

If you do this, be SURE to re-label the output jacks so that somebody (including you) down the road is not misled but your new connections.

 

[Dynacord]

Late to the party on this but wanted to mention that Jeff Fisher at Rerun Electronics in Berlin does great work on these amps. I have the very same model after he went through it and swapped the DIN input jacks and the sort of banana plug speaker outs for 1/4" jacks all around: well labeled 4 ohm AND 8 ohm speaker outs.

Really great amp IMO - super solid build, only 10 kg, global voltage selection, etc. I still have all the paperwork that came with it originally (in German).