Using a 110v rated Tube amp with 220v - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 
Thread Tools
post #1 of 6 Old 12-21-2015, 04:12 AM - Thread Starter
Newbie
 
Join Date: Dec 2015
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 0
Unhappy Using a 110v rated Tube amp with 220v

Hi Guys

Thank you in advance for helping me with what you know.

I bought this tube amp from Monoprice. I'm based in Singapore and we have 220V/240V, 50 Hz. I bought this while traveling to US to save on shipping cost and also because they have mentioned in the page that it is indeed compatible with 220v.

I'm unable to post a URL here. If you want to see the description on Monoprice, go to monoprice website and search for "Stereo Tube Amp System with Bluetooth® and Speakers". Product Number 13807.

I came back home and plugged it in and the fuse got burnt out. Bought step down transformers 300w and 100w, tried with both. The amp powers up, bluetooth signal is going through (I know this coz the VU meter is moving), but only hear a hum through the speakers. I tried this in the US and worked fine.

Contacted them Monoprice customer support and I was asked to change the fuse to F1AL/250V. Tried that and the fuse was burnt again. With the step down transformer, still get a hum. Even through the headphones, I get a hum. No music is playing.

All the tubes work fine.

Any way I can get this to work? RMA is not an option coz it costs me about $200 to ship it back to US, which is almost the same price as buying a new one. This is a well made amp and I just don't have the heart to throw it away and waste the $200 I spent on it.

Any help would be greatly appreciated. Thank you all!
Shevon Perera is offline  
Sponsored Links
Advertisement
 
post #2 of 6 Old 12-21-2015, 03:02 PM
AVS Forum Special Member
 
Join Date: Jan 2015
Location: United States
Posts: 2,592
Mentioned: 52 Post(s)
Tagged: 0 Thread(s)
Quoted: 1297 Post(s)
Liked: 2097
Your power supplies must love you!

I would check the voltage on the power supplies to see if any of them are damaged. Make sure the step down transformer is a transformer, those converter things don't work well with audio gear. Since you are running it at 120V 50Hz through a step down, the fuse should be the same size as stock. If the stock size is 2 amps, use that rating with a step down transformer.

Your amp has a tube pre-amp and a solid state output amplifier. Check the power supplies and, if you can--the output transistors. If you have a friend that knows a bit about electronics, they can test the output transistors, bridge diodes and power supply voltages for a quick once over. Good luck!
18Hurts is online now  
post #3 of 6 Old 12-21-2015, 03:17 PM
Advanced Member
 
cookieattk's Avatar
 
Join Date: Jun 2011
Posts: 688
Mentioned: 2 Post(s)
Tagged: 1 Thread(s)
Quoted: 111 Post(s)
Liked: 92
Input Voltage Range 100 ~ 120 VAC, 50/60 Hz
220 ~ 240 VAC, 50/60 Hz

u dont need to stepdown anything just plug it in.
cookieattk is offline  
Sponsored Links
Advertisement
 
post #4 of 6 Old 12-21-2015, 05:42 PM - Thread Starter
Newbie
 
Join Date: Dec 2015
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 0
Quote:
Originally Posted by 18Hurts View Post
Your power supplies must love you!

I would check the voltage on the power supplies to see if any of them are damaged. Make sure the step down transformer is a transformer, those converter things don't work well with audio gear. Since you are running it at 120V 50Hz through a step down, the fuse should be the same size as stock. If the stock size is 2 amps, use that rating with a step down transformer.

Your amp has a tube pre-amp and a solid state output amplifier. Check the power supplies and, if you can--the output transistors. If you have a friend that knows a bit about electronics, they can test the output transistors, bridge diodes and power supply voltages for a quick once over. Good luck!
18Hurts

Thanks for the response. Reading your response, I think what I have is a converter. Not a transformer. That could be the issue. I'll go and try to buy another today. What's the difference actually?
Shevon Perera is offline  
post #5 of 6 Old 12-21-2015, 05:43 PM - Thread Starter
Newbie
 
Join Date: Dec 2015
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 0
Quote:
Originally Posted by 18Hurts View Post
Your power supplies must love you!

I would check the voltage on the power supplies to see if any of them are damaged. Make sure the step down transformer is a transformer, those converter things don't work well with audio gear. Since you are running it at 120V 50Hz through a step down, the fuse should be the same size as stock. If the stock size is 2 amps, use that rating with a step down transformer.

Your amp has a tube pre-amp and a solid state output amplifier. Check the power supplies and, if you can--the output transistors. If you have a friend that knows a bit about electronics, they can test the output transistors, bridge diodes and power supply voltages for a quick once over. Good luck!
How many watts do I need? I have no idea how to figure this out.
Shevon Perera is offline  
post #6 of 6 Old 12-22-2015, 08:00 AM
AVS Forum Special Member
 
Join Date: Jan 2015
Location: United States
Posts: 2,592
Mentioned: 52 Post(s)
Tagged: 0 Thread(s)
Quoted: 1297 Post(s)
Liked: 2097
Quote:
Originally Posted by Shevon Perera View Post
How many watts do I need? I have no idea how to figure this out.
I looked up your hybrid amp they call it--uses tubes for the preamp and is rated 15 watts per channel into 4 ohms. The fuse for 120V is 2 amps so look for a transformer around 300 watts if device can't be switched to 220/240V.

However, if it is rated 120V and 220/240, that usually implies it has a switch to change it from 120 to 220V. Sometimes that means the thing can be wired for 220V internally so becomes quite confusing. The only ones that can be plugged into anything are rated along the lines of this rating: 100 - 240 or 80-270V etc.

I went to Europe 25 years ago and my amplifier had to be rewired by moving jumpers in the power supply to run on 220V--there was no switch. One of those 100 - 120V and 220-240V see manual kind of things.

What I learned from that is those little converter things are fine for basic things but not for sensitive electronics--they will cause hum, most electronics won't work sort of thing.

If I was you, I would contact Monoprice and ask them how to change it to run on 220V since it is listed in the manual. How it does this depends on design be it a switch, internal jumper change or whatever. Change the fuse from 2A to 1A as 220 requires half the current of 120.

Hope it works for you once it is powered correctly, if not--then look at the power supplies first and home they did not spike and blow the output transistors. Good luck!
18Hurts is online now  
Sponsored Links
Advertisement
 
Reply DIY Speakers and Subs

Tags
220v to 110v , amplifier , amplifier not working , step down transformer , tube amp

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off