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RPX-100 owners : Need Help

post #1 of 21
Thread Starter 
Calling all RPX-100 onwers:

The heat vents on my RPX-100 is on the front side (closer to the front face plate) which is obviously different from what I have seen on Rudistor website.

I am show pics of how it looks like front and back, and would like ask owners of existing RPX100 to tell if you amp is anything different (especially on the back side because I am not sure if it is a simple thing for reinstalling the cover plate).





I have tried to contact Rudistor services but was given a rude, arrogant response which is far from helpful. That's why I need to seek help here.

Many thanks in advance.

F. Lo
post #2 of 21
Quote:
Originally Posted by fkclo View Post
Calling all RPX-100 onwers:

The heat vents on my RPX-100 is on the front side (closer to the front face plate) which is obviously different from what I have seen on Rudistor website.

I am show pics of how it looks like front and back, and would like ask owners of existing RPX100 to tell if you amp is anything different (especially on the back side because I am not sure if it is a simple thing for reinstalling the cover plate).

I have tried to contact Rudistor services but was given a rude, arrogant response which is far from helpful. That's why I need to seek help here.

Many thanks in advance.

F. Lo

Fkclo

Checking out the Rudistor web site and looking at their picture the vents are toward the back side unlike the one you have shown. BUT....looking at an expanded look at the internals would indicate that the vents should be forward since the hot parts are the big power transistors with heat sinks. These are shown forward nearer the front. To my thinking it would be best to have the vents above the hottest parts of the unit; i.e., those transistors. Question, are there vents in the bottom of the cabinet so that air would be able to travel from below to the top of the unit? If you have bottom vents they may be toward the back allowing ventilation across the box with heat sinks almost in the last part of the air flow. Again looking at the internal picture expanded I see that the web site unit shows its vent toward the back as would be expected for best air flow. For the one on the web site those heat sinks would be bypassed with the air flow going straight up and not across those heat sinks.

My AT-HA5000 has vents above and below its MOSFET transistors and heat sinks for this purpose.

From what I know yours is the best arrangement of the two.
post #3 of 21
Not sure whom answer you in the Rudistor lab, but definitelly was not Rudi, they are far from being rude, not even while he is really busy and overwhelmed. I will drop them an email, to see who was the one who answered you, and get him or her corrected, I promise you that...

I apologize for that answer, and I will answer you.

Definitelly this cover is reversed, please just remove the screws on top, and place it with the vents to the back. This is not a big deal and this will not affect the amp in any way, it is more like a cosmetic issue. But definitelly it is not the right way. If you take a close look you will see that there is a fold along the plate, that right now is over the back panel, that should go to the front, as it is intended to reinforce the sheet on that area, as on the back it rests over the back panel...Just be careful as the nuts are inserted on an slot that runs all along the sides, and they will slide while removing them. When you remove it, just place the cover on top the right way and realign the nuts with the holes and reattach it agai nwith the screws, it is indeed a two minutes work...

Sorry for the troubles and please if any other problem arises just drop me an email or a PM....
post #4 of 21
Thread Starter 
Quote:
Originally Posted by slwiser View Post
To my thinking it would be best to have the vents above the hottest parts of the unit; i.e., those transistors. Question, are there vents in the bottom of the cabinet so that air would be able to travel from below to the top of the unit? If you have bottom vents they may be toward the back allowing ventilation across the box with heat sinks almost in the last part of the air flow. Again looking at the internal picture expanded I see that the web site unit shows its vent toward the back as would be expected for best air flow. For the one on the web site those heat sinks would be bypassed with the air flow going straight up and not across those heat sinks.

My AT-HA5000 has vents above and below its MOSFET transistors and heat sinks for this purpose.

From what I know yours is the best arrangement of the two.
Thanks slwiser,

The PRX-100 has vent holes also in the bottom, these are towards the rear. Initially I think mine has a clever design - because cold air will rise through the bottom holes, carries the heat, and then escape the box through the vent slots in a diagonal fashion. My mechanical engineering training tells me this will provide the best convective flow path covering most heat generating components inside the box. Until I double check the website.

Regards,
F. Lo
post #5 of 21
Thread Starter 
Quote:
Originally Posted by Sovkiller View Post
Not sure whom answer you in the Rudistor lab, but definitelly was not Rudi, they are far from being rude, not even while he is really busy and overwhelmed. I will drop them an email, to see who was the one who answered you, and get him or her corrected, I promise you that...

I apologize for that answer, and I will answer you.

Definitelly this cover is reversed, please just remove the screws on top, and place it with the vents to the back. This is not a big deal and this will not affect the amp in any way, it is more like a cosmetic issue. But definitelly it is not the right way. If you take a close look you will see that there is a fold along the plate, that right now is over the back panel, that should go to the front, as it is intended to reinforce the sheet on that area, as on the back it rests over the back panel...Just be careful as the nuts are inserted on an slot that runs all along the sides, and they will slide while removing them. When you remove it, just place the cover on top the right way and realign the nuts with the holes and reattach it agai nwith the screws, it is indeed a two minutes work...

Sorry for the troubles and please if any other problem arises just drop me an email or a PM....
Sovkiller,

Thanks for your kindness.

I send the photos to Rudistor customer service explaining my observation and my worries (wrong assembly, and may be wrong slotting of the holes) in an elaborated, patient manner. The gentleman responding then suggested
" Probably you have a very limited experience on hi-end Class-A amplifiers but trust us, it works correctly as it is." .. Then later he warned me that "Any attempt to modify the product will immediately void the warranty as for international legal trade rules on warrantee matter" which was far from what I expected. I was shocked.

Actually, I thought the fold at the top edge of the top plate was more to reinforce the plate at the back which is why I thought someone stamp the slots in the wrong position. The top-plate will be well backed up by the face plate so I did not think it was for the reinforcement of the front.

Then I wrote again trying to tell him I haven't touched the amp, not to mention modifying it, I got this reply today:-

" Your Amp has been assembled correctly All the description and official picture show it.
Although minor change can happen between productions lot, your it totally coherent to what we offered and never we have showed or proposed the amp with cover mounted on the wrong side as you did. THE VENT HOLES MUST BE IN THE REAR. STOP!!"


And my interpretation is that he is asking me to stop consulting him on this issue. For him the case is closed.

Although some may not say this is rude. I am quite taken surprised by the attitude displayed between the lines. Well, may be my English was poor, or something else.

Since I will open up the amp to share pictures of the internals with fellow head-fiers, I will try to unscrew the top plate to see if it fits properly.

Thanks again. But this is definitely new experience to me on customer service to the most expensive amp I acquired to-date.

F. Lo
post #6 of 21
For you viewing entertainment:



If it we me as a designer I would want a shield between those transformers and the rest of the electronics but that would mess up the air flow. But I guess it could be rapped around making a 90 degree turn toward the back. But I really don't believe in messing with a unit to much due to warranty issues. Other than this slight design oversight it looks like a real nice dual mono amp as it is, especially having balance output at the same time. Can you use three headphones at the same time with this unit?

Those transformers have a larger footprint for EMI than the R-core transformers used in my AT-HA5000.

When you put up your photos we can compare the two....neat. Does simply opening the unit violate the warranty?

BTW, those caps are the same color and look as the one in my Xin Reference. Those in my AT-HA5000 are gold and black.
post #7 of 21
Deleted post.
post #8 of 21
Quote:
Does simply opening the unit violate the warranty?
No. I opened both my Rudistor amps, and Rudi had no problems with that. Perhaps he's on holiday, this sure doesn't sound like him.
post #9 of 21
Thread Starter 
Hi all,

Thanks for Sovkiller comment. I just reinstall the top plate as suggested. I hope this is a small issue. No the person responding for Rudistor is NOT Dr. Rudi but I do not want to name names here.

I thank all for all the helpful ideas and believe I've got the solution. It is only a few minutes work and I also took the opportunity to try out a new pair of KAS Audio Meastro XLR IC - link the balanced output of my Benchmark DAC1 and the balanced input of the PRX-100.

Sure, this is not the "perfect" customer service case but none the less Rudi did PM me to confirm the proper orientation of the vent slots. Regardless of my bitter experience, I must say Rudi is a gentleman and I can only hope he has the time to take care of his followers.

As business like Rudistor grows the weak links like customer service do not always catch up with the growth and that sometimes can create bad experiences. Anyway, I hope all learned something and once again, thanks to all the folks here - without your help I will be at a lost.

Regards,
F. Lo
post #10 of 21
Thread Starter 

Case Close

Rudi just wrote to review the case and we agree this is more a matter of miscommunication than any ill intent involved.

Obviously when English is not native my way of expression may not necessarily interpreted correctly, and vice versa from Rudistor end.

I would call this a close case and hopefully everything will be a smooth ride from now on.

F. Lo
post #11 of 21
Mine as the slots to the back. From your photo it appears you have one screw each side I have two each side.
post #12 of 21
Thread Starter 
Mine actually also has two screws on each side.

The rear screw was just block by the arcylic shelf creating an illusion.

F. Lo
post #13 of 21
So, it was just a matter of the top plate being in the wrong orientation?

Was the amp purchased brand new, or used? If used, the obvious culprit was the previous owner.
post #14 of 21
Think it was bought new.
post #15 of 21
Thread Starter 
It is brand new.

Have communicated with Rudi who told me that their assembly procedure made it impossible to install the plate in the wrong orientation.

The only possibility is the customs inspection. My package did carry a seal by local customs indicating the box was opened and inspected, but there is no solid proof that they did open up the case, but obviously they are the prime suspect.

Anyway, it is all over now. I was concerned because I thought may high end design would prohibit components to be installed in a wrong position, so I was presuming the top plate was wrongly stamped. But it turns out the plate can be installed the other way round, and the problem was solved.

Obviously, miscommunication was the key problem in this case.

But then again, I still think it makes sense to have a cross conventive flow inside the box (bottom and top vent slots in diagonal position) , because this will dissipate heat within the enclosed volume most effectively, although this is not very common in audio equipment.

F. Lo
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