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Trace Elliot Boxer 65 Combo Voltage change

J

JohnBayse

Mar 25, 2024
8
0
#1
So I have this bass amp that was purchased in Hong Kong years ago and works on 230 volts. I want to get it to work at 110/20 volts without a step transformer. Any advice would be welcome.

Info:
230 50/60Hz
T1A 250V power fuse

Other listed voltages:
100 volts = T2A
110 volts = T1.6A
230 volts = T2A

Inside the unit:
PC Board has two empty Fuse Slots...FS1 and FS2
Accepted fuse types for these slots are T2A or T1.6A

Note: I will post some snapshots of the amp and its insides later.

Thank you
 
#2
You might want to contact Trace Elliot and find out whether a multi-tap transformer was used. If not, you will need to replace the transformer, which might be cost prohibitive in comparison to buying a new combo.


[Invalid or Expired Link Removed]
For questions concerning product operation, support, and warranty:
Trace Elliot
5022 Highway 493 North
Meridian, MS 39305
Phone: (877) 856-9243
Fax: (601) 486-1278
E-Mail: [email protected]
 
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#4
I tried calling that number and I was connected to someone at Peavey. They said that Trace just handed them the company and said "here it is...you figure it out." Transformer is not multitap. Does anyone know what the two fuse slots on the PCB are for? Since I first took a look, I don't recall any fuses installed.
 
#5
JohnBayse said:
I tried calling that number and I was connected to someone at Peavey. They said that Trace just handed them the company and said "here it is...you figure it out." Transformer is not multitap. Does anyone know what the two fuse slots on the PCB are for? Since I first took a look, I don't recall any fuses installed.
Click to expand...


I did a quick search and found this: 1.PDF (someinfos.de)

If I am reading the circuit right, FS1 and FS2 transfer AC from the power transformer to the bridge rectifier.

upload_2024-3-31_2-30-11.png


I did not see anything in the document discussing the power transformer or how to adjust taps for different regions. However, that does necessarily mean it can't be done.

The Trace Elliot V8 Service Manual does not show this info either, but the transformer is labeled.
upload_2024-3-31_2-36-15.png

Image from @disssa

I switched my V8 from Euro voltage (240V) to US voltage (120V). This was in 2012, so I don't remember the specifics.

Keep in mind the V8 was there flagship tube amp...and the Boxers were their budget line. It's likely the voltage is not switchable on the Boxer without replacing the power transformer. It's unlikely that you will find and OEM transformer and the cost to swap it out would be more than the amp is worth IMHO.
 
#6
If I were to find an OEM transformer, can I just put it in...or will I have to change/adjust/calibrate other components? Everyones right it may not be worth my trouble. If I go with a step up transformer that supplies 220/240v, what about the FS1 and FS2, that has me lost....
 
#7
I don't believe the value of FS1 and FS2 changes. A proper transformer will covert the voltage at these fuses to whatever the circuit needs. I found an image and it looks like it says 2A for 65W. 1.6A is used for the lower power models.
upload_2024-3-31_13-46-53.png



The value of the main power fuse does change. When the voltage is cut in half, the current increases.

I found this image for a Boxer 65 online.
upload_2024-3-31_13-43-0.png


I think if a tech installed the new transformer, they would probably consider checking the bias of the output stage...I am not an expert, but I don't see a bias adjustment or suggested readings on the schematic for the output stage. However there is no guarantee that is the correct schematic for your amp. There could be revisions that have a bias adjust.
 
#8
I am definately going to stick with a step up transformer that can supply anywhere from 220 to 240. Since this amp is the 65W model, I would have to have T1.6 Fuses in FS1 and FS2. Main Power Fuse Remains at T1A for 230V. Am I correct? Here is a picture of the back of the amp.
IMG_0204.jpg
 
#9
Why is FS1 and FS2 empty? Is there more to the story?

if it’s working without the fuses, this means that they weren’t used in this version (possibly because the transformer is separately protected).
 
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#10
Great question. I just don't remember taking them out. I am sure I would have left them in. I am thinking it worked without the fuses. Shortly after I purchased it in Hong Kong, I plugged it into a 120V outlet along with a step up transformer (one of the small electric shaver types, not a big heavy one), and it stopped generating sound but the on/off switch was still lit. And it has been in that condition ever since.
 

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