Hello all!
I have a Peavey Classic 30 BT, I believe its a 2002 model.
The amp uses a 16 ohm speaker and there is a jack for an external speaker.
I just built a speaker isolation cabinet which has an 8ohm speaker and I wish to avoid buying another speaker if I can.
Here's my question: Looking at the schematic, assuming there is only one schematic for all Classic 30's, it appears that the main speaker and the external speaker jack are wired in parallel. Now the schematic has a notation for the external speaker showing 8ohms.
Sorry if this is a stupid question but, that is an indication that the load for all speakers connected, be it one or more, has to be 8ohm minimum, correct?
If I am reading this correctly that would mean that I can use an 8ohm speaker as long as its used solo, correct?
If that is correct, does that mean I can disconnect my speaker wires and plug the ISO box in to the external jack and all will be fine? Or is there some reason I need to use the main speaker wiring for the 8ohm load?
I need someone that knows what they are talking about to help me because I'm gonna fall apart of I mess up my Classic 30, its my baby!
Thanks for your help!
BR.
I have a Peavey Classic 30 BT, I believe its a 2002 model.
The amp uses a 16 ohm speaker and there is a jack for an external speaker.
I just built a speaker isolation cabinet which has an 8ohm speaker and I wish to avoid buying another speaker if I can.
Here's my question: Looking at the schematic, assuming there is only one schematic for all Classic 30's, it appears that the main speaker and the external speaker jack are wired in parallel. Now the schematic has a notation for the external speaker showing 8ohms.
Sorry if this is a stupid question but, that is an indication that the load for all speakers connected, be it one or more, has to be 8ohm minimum, correct?
If I am reading this correctly that would mean that I can use an 8ohm speaker as long as its used solo, correct?
If that is correct, does that mean I can disconnect my speaker wires and plug the ISO box in to the external jack and all will be fine? Or is there some reason I need to use the main speaker wiring for the 8ohm load?
I need someone that knows what they are talking about to help me because I'm gonna fall apart of I mess up my Classic 30, its my baby!
Thanks for your help!
BR.
There are both 16 and 8 Ohm taps available, so wire the plug for the 8 Ohm speaker. It's pin 3 on jack J4.
Schematic
Apparently the schematic is larger than the limit allowed. So here is a link to my server where you can download it if needed.
Index of /Classic30
Apparently the schematic is larger than the limit allowed. So here is a link to my server where you can download it if needed.
Index of /Classic30
Rayma thanks for the reply. So j4 (the external jack) is already wired for both, how do I access it?
And the idea here is to send all speaker signal to my ISO box and none to the speaker in the amp.
I have connected a 16 ohm cab to the external jack before and it plays both the internal and external speakers, even though the schematic looks like connecting to the external jack is supposed to disconnect the internal speaker.
What gives here?
And the idea here is to send all speaker signal to my ISO box and none to the speaker in the amp.
I have connected a 16 ohm cab to the external jack before and it plays both the internal and external speakers, even though the schematic looks like connecting to the external jack is supposed to disconnect the internal speaker.
What gives here?
Maybe someone rewired or replaced the jack. Is it still a regular 1/4" stereo phone jack? There should be a built-in switch on the jack to disconnect the internal speaker from the 16 Ohm tap. They may have moved a wire, so check the J7 and J13 wiring and compare it with the schematic.
The easiest thing is to disconnect the wires from pins 1 and 3 of the terminal J7. Then when you plug in the external cable,
it should only connect to the 8 Ohm tap, which is the J10 terminal on the output transformer. If the internal speaker still works,
they've rewired it differently from the schematic. It's hard to tell if the 8 Ohm tap is connected to the ring or tip of the phone plug,
but I'd guess that the ring is the 8 Ohm tap.
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Here is what the blue guitar guy has to say.
(snip)
Another solution might be to add a jack for the built-in speaker so that you could unplug it and use anexternal speaker when you need to crank the amp up loud. I drilled a hole below the power switch andindicator light for a speaker jack (connect the yellow wire to the hot terminal and the blue wire to the ground terminal). The added jack is connected to the 16 ohm tap, the existing jack is connected to the 8 ohm tap,and if you plug into both jacks, they are connected in parallel to the 8 ohm tap. This last mods makes theamp much more versatile.
I strongly recommend that you replace the stock 12" 16 ohm speaker. (I put in an 8 ohm Celestion V12-60 "Silver Series" for about $60 and was fairly pleased with the performance.) What I did notice when I put the stock speaker back in, the amp sounds much more alive if I plug it into the existing "Extension Speaker"jack (which uses the 8 ohm tap). I also noticed a similar response when testing the amp with the 16 ohmload of my Classic 50-410 speakers. I suspect that putting the speaker load on the 8 ohm tap has an effect on the feedback loop; in any event, for a nice blues lead guitar tone use the 8 ohm jack whenever feasible.
There is a simple trick to switch the built-in speaker from the 16 ohm tap to the 8 ohm tap: plug a bare1/4" plug into the Extension Speaker jack. The internal switching contacts of the jack will connect the built-in speaker in parallel to the 8 ohm tap when anything is plugged into the Extension Speaker jack. If you can't afford to replace the stock speaker at this time, be sure to switch it over to the 8 ohm tap. (snip)
Here is the link:
http://blueguitar.org/new/articles/blue_gtr/amps/peavey/c30_origmod.pdf
Careful, if you go to take it out of the cabinet. It is the biggest POS
I've ever worked on. Well maybe not but close. It will start to break apart
before your eyes if you work on it.
When they start to really sound like SCHEISSE you get the joy
of replacing the tube sockets. Arching starts and they can't be fixed.
Aside from that, gook luck.
Cheers,
(snip)
Another solution might be to add a jack for the built-in speaker so that you could unplug it and use anexternal speaker when you need to crank the amp up loud. I drilled a hole below the power switch andindicator light for a speaker jack (connect the yellow wire to the hot terminal and the blue wire to the ground terminal). The added jack is connected to the 16 ohm tap, the existing jack is connected to the 8 ohm tap,and if you plug into both jacks, they are connected in parallel to the 8 ohm tap. This last mods makes theamp much more versatile.
I strongly recommend that you replace the stock 12" 16 ohm speaker. (I put in an 8 ohm Celestion V12-60 "Silver Series" for about $60 and was fairly pleased with the performance.) What I did notice when I put the stock speaker back in, the amp sounds much more alive if I plug it into the existing "Extension Speaker"jack (which uses the 8 ohm tap). I also noticed a similar response when testing the amp with the 16 ohmload of my Classic 50-410 speakers. I suspect that putting the speaker load on the 8 ohm tap has an effect on the feedback loop; in any event, for a nice blues lead guitar tone use the 8 ohm jack whenever feasible.
There is a simple trick to switch the built-in speaker from the 16 ohm tap to the 8 ohm tap: plug a bare1/4" plug into the Extension Speaker jack. The internal switching contacts of the jack will connect the built-in speaker in parallel to the 8 ohm tap when anything is plugged into the Extension Speaker jack. If you can't afford to replace the stock speaker at this time, be sure to switch it over to the 8 ohm tap. (snip)
Here is the link:
http://blueguitar.org/new/articles/blue_gtr/amps/peavey/c30_origmod.pdf
Careful, if you go to take it out of the cabinet. It is the biggest POS
I've ever worked on. Well maybe not but close. It will start to break apart
before your eyes if you work on it.
When they start to really sound like SCHEISSE you get the joy
of replacing the tube sockets. Arching starts and they can't be fixed.
Aside from that, gook luck.
Cheers,
@Badraven,
What happened with your amp?
Hopefully you were able to get it the way you wanted.
Let us know what you found out, what you did and what
difference it made.
Cheers,
What happened with your amp?
Hopefully you were able to get it the way you wanted.
Let us know what you found out, what you did and what
difference it made.
Cheers,
Results of using an 8ohm speaker
Sorry, I should have shared this.
I contacted tech support at Peavey and asked them about using an 8ohm speaker. Since their reply I have been using an 8ohm speaker for several weeks now and no problems so far. I use my ISO box with an 8ohm G12T-75 and it sounds great! Following is the response from Peavey.
Hello Jeff,
Thanks for your support of Peavey tube guitar amplifiers !
The Classic 30 is rated at 30 watts into 16 ohms and 8 ohms.
The internal speaker is 16 ohms. The external speaker is recommended to be another 16 ohms, also. Because two 16 ohm speakers wired in parallel on the same amplifier output is 8 ohms. If you connect a 8 ohm extension speaker with the internal 16 ohm speaker then the total load will be 5.3 ohms. In this case the amp will operate at a higher temperature and this can shorten the life of the tubes. One possibility is that you can just use a single 8 ohm speaker load. You can disconnect the internal 16 ohm speaker and connect a 8 ohm extension speaker load to the amps extension speaker jack. If you do this then be sure and insulate the internal speaker wire leads /connectors so that they don't " short out " on themselves, the internal speaker magnet, or the amps metal chassis. Some may want to replace the internal speaker with a 8 ohm speaker. In this case connect the 8 ohm speaker to the extension speaker output jack.
Thanks,
Aubrey
Sorry, I should have shared this.
I contacted tech support at Peavey and asked them about using an 8ohm speaker. Since their reply I have been using an 8ohm speaker for several weeks now and no problems so far. I use my ISO box with an 8ohm G12T-75 and it sounds great! Following is the response from Peavey.
Hello Jeff,
Thanks for your support of Peavey tube guitar amplifiers !
The Classic 30 is rated at 30 watts into 16 ohms and 8 ohms.
The internal speaker is 16 ohms. The external speaker is recommended to be another 16 ohms, also. Because two 16 ohm speakers wired in parallel on the same amplifier output is 8 ohms. If you connect a 8 ohm extension speaker with the internal 16 ohm speaker then the total load will be 5.3 ohms. In this case the amp will operate at a higher temperature and this can shorten the life of the tubes. One possibility is that you can just use a single 8 ohm speaker load. You can disconnect the internal 16 ohm speaker and connect a 8 ohm extension speaker load to the amps extension speaker jack. If you do this then be sure and insulate the internal speaker wire leads /connectors so that they don't " short out " on themselves, the internal speaker magnet, or the amps metal chassis. Some may want to replace the internal speaker with a 8 ohm speaker. In this case connect the 8 ohm speaker to the extension speaker output jack.
Thanks,
Aubrey
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