PRP Resistor Problems

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jameshuls

PRP Resistor Problems
« on: 14 Apr 2009, 04:14 am »
For anyone who has purchased PRP resistors lately, make sure to check them with a multimeter. I checked all of my 1/4 W resistors for upgrading my piccolo and all of the 470R were actually 470K. Also, one of the 330Rs measured at 230R. Otherwise, they all were within 1%. I have contacted Parts Connexion for replacement. Their customer service seems quite good so I don't foresee issues in replacing them. I'm glad I checked now, as once in the circuit it would have been a pain to replace and I wouldn't have received a refund, since they expect you to check them before installation.

tubesforever

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Re: PRP Resistor Problems
« Reply #1 on: 15 Apr 2009, 06:46 am »
Great advice James!

I too thought I might want to test all my Piccolo and Bugle P/S caps and match them closely on the board positions.

Well all 4 of my 490R resistors were bad.  Two measured 467k ohms, one measure 525k ohms and the last resistor measured 535k ohms. 

I had a pair of 390R resistors I bought for cartridge loading and one was good at 388 ohms and the other was terribly off at 318 ohms.

Others planning on using these terrific PRP resistors should definitely test each resistor until the news comes out that they are all tested and confirmed. 

So far from the sound of my Piccolo project I am very pleased with the PRP resistors.  They sound clear and clean.  These fairly inexpensive film resistors provide a big sonic improvement over the stock specified resistors in my opinion.

Cheers!

hagtech

Re: PRP Resistor Problems
« Reply #2 on: 15 Apr 2009, 04:33 pm »
Interesting.  I had problems with PRP when I used them in the GOLD TRUMPET a few years ago.  Had some go open on me, thought I may have bent the leads too much.  Never did figure out exactly what happened.

jh

PatOMalley

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I can't rest now
« Reply #3 on: 17 Apr 2009, 11:07 pm »
So close. I used the PRP in the RIAA signal.
After all this out of spec stuff I can't rest using them.
New resistors from TAKMAN are carbon and metal film. I am going to swap out the PRP for the carbon/film.
And I was soooooooo close.
Got the tranny bought and screwed down to the top place with nice brass screws.
I got JH to OK Lansing to cut the chassis but they wanted too much $$$.
So I got Mr Jim l'Tubesforever to cut the chassis for me with a lot of nice touches.
I must have some kind of subliminal fear of success going on.


tubesforever

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Re: PRP Resistor Problems
« Reply #4 on: 18 Apr 2009, 05:52 am »
Pat,

I find that the PRP resistors sound very clear and very detailed in my Piccolo.  In fact it leaves nothing on the table compared to my CineMag SUT. 

Michael Percy said the PRP's are so good they can second for the Vishay's in many builds.  I believe this now that I have used them.  With the S102 nude Vishays at 11.95 a piece that is MUSIC to my pocket book.

If the resistors as they sit on your board right now spec out,  I doubt you will ever have a problem or an issue.  All but just a couple of resistors should measure out fine with your DMM.  There are a couple of resistors hiding behind a cap that will change value as the capacitor fills up.  These are probably OK to use if they measure the same in both channels.

In my Piccolo the PRP's sound so clear and clean that I would not replace them with anything.  That said Pat, I want you to do what your heart tells you to do on this build.  At least with the C2 if you swap out all the resistors you are not likely to lift any PCB traces. 

On a cautionary note, make sure you get the original piece nice and hot so it pulls without resistance from the board.  I generally set my iron about 100 degrees higher when removing stuff than when I am soldering the items in.  My idea is that I want both traces to be molten before pulling the resistor or capacitor.

I clean up the traces with number two no clean copper wicking.  This stuff is simply amazing.  In many cases you never could tell anything was ever soldered to the board in the first place.

The PRP resistors sound good enough to recommend.  Don't let their QC issues dissuade you from trying them.  This is a new product line and people are not testing the final product for their values.  Like James said, they probably just mislabeled the 470k as 470R.   

Good luck with your build Pat.  Try out those PRP's before you ditch them.  I think you will be more than satisfied with their sonics.

Cheers!

PatOMalley

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Re: PRP Resistor Problems
« Reply #5 on: 19 Apr 2009, 05:58 pm »
Tubes,

Remember when the 'old man' told you to do something or to NOT do something?
Besides, no one yet has posted about the TAKMANs around here so ...

galyons

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Re: PRP Resistor Problems
« Reply #6 on: 19 Apr 2009, 06:41 pm »
The Takman's have received pretty good press.  As well, the KOA-Speers, (purportedly the makers of Kiwame).  I used PRP's in my Piccolo build, now a couple of years ago. As has been reported, they are very good.  I also did the Kiwame/PRP thing in the Cornet 2. Now....

As a side note, Rogue Audio has announced an upgrade to my M-150 monoblocks. The upgrade includes  beefing up the power supply & caps, (I already had this done!), bypassing the 'lytics with polypro's, (I already had this done!), using Cardas binding post, (I already did this!) and....replacing all of the Vishay Dales in the signal path with PRP's!  They add in KT90 versus 88, some upgraded small signal tubes, (I obviously did this first!!  I replaced the Mundorf caps with Russky PIO's.).   The M-150's are now M-180's for only $1295.00 plus shipping back & forth to Rogue, (approx $400 from CA).  I had already replaced the grid resistors with PRP, now I will map and replace all of the signal path Vishay Sales! 

The word is getting out about the PRP's.  Pat, do get us the word on the Takmans!

So many possibilities, so little available ca$h!!

Cheers,
Geary

WGH

Re: PRP Resistor Problems
« Reply #7 on: 19 Apr 2009, 07:26 pm »
Pat,

A solder sucker works great at removing molten solder before pulling off parts. They are available all over for $5-$10.



Wayne

PatOMalley

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Re: PRP Resistor Problems
« Reply #8 on: 19 Apr 2009, 09:33 pm »
Know what? I may just start up with the PRPs as is to get a feel then swap after a couple of weeks for the Takmans so I can have some kind of comparison. I remember someone in the past swapping out resistors and they posting that the swap to better ones had no effect; but in this case we are going from metal film, to carbon film.

WGH,
I might fetch one of those solder suckers. I now use solder wick and it really gets the job done like there was no solder there at all on the C2 board.


The Takman's have received pretty good press.  As well, the KOA-Speers, (purportedly the makers of Kiwame).  I used PRP's in my Piccolo build, now a couple of years ago. As has been reported, they are very good.  I also did the Kiwame/PRP thing in the Cornet 2. Now....
[snip]
The word is getting out about the PRP's.  Pat, do get us the word on the Takmans!

So many possibilities, so little available ca$h!!

Cheers,
Geary

jameshuls

Re: PRP Resistor Problems
« Reply #9 on: 20 Apr 2009, 12:29 am »
Quote
I may just start up with the PRPs as is to get a feel then swap after a couple of weeks for the Takmans so I can have some kind of comparison

That's the spirit! The more we all experiment, the more we'll all get out of this phenomenon that Mr. hagerman has created. make sure all your caps have burned in though - I experienced some significant changes in character that would have overshadowed any subtle changes wrought by a change in resistors.

RE: the solder sucker, I use one with the copper wicking, depending on the situation. I find that neither one is ideal in all situations, but they complement each other nicely. I got one of the cheap bulb type - I think it was only a couple of bucks.
« Last Edit: 20 Apr 2009, 04:10 am by jameshuls »

bluesky

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Re: PRP Resistor Problems
« Reply #10 on: 20 Apr 2009, 02:02 am »
Hi Tubes

Can you tell me where to source that number 2 solder wicking stuff, I have never heard of this before.  I often have to pull parts out when doing various upgrades for some of my audio buddies.  At one stage I used a fancy desoldering station for a while and it broke down.  I did get it replaced under warranty and then it broke down again, just two weeks after the warranty ran out!

Since then I have tried a few different solder suckers and settled on one like the above with reasonable success but I'm always on the lookout for better products to help me with my audio building hobby.  I also use one of those lithium battery powered cordless screw drivers rated at 4.8V which has become indispensable.  Apart from srewing in and out I often use it with a tiny drill chuck with either a 0.8mm or 1.0mm drill bit to enlarge the hole which is often clogged with solder remnants.  As a matter of course I always measure resistors prior to soldering, it becomes a habit after a short time. 

Lastly, I have to state that Jim's PCB's are without doubt the best I have ever come across, not only for the quality of manufacture but also the layouts on the PCB's itself which makes stuffing parts a joy.  I think this is also partly due to the tube topology being much larger than comparable solid state designs where you often need to cram parts in.  This is especially so with a lot of Black Gates or film caps which are usually much larger than the original industrial grade parts.

Cheers

Bluesky

tubesforever

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Re: PRP Resistor Problems
« Reply #11 on: 20 Apr 2009, 06:07 am »
Sorry Pat,  You can kick me at Mike's Ribfest. 

As far as the sound on the PRP resistors go, I think that the PRP resistors really are as great sounding as the hype I have heard so far.  The low level detail I am hearing is sick!  I love it Pat.  The noise floor of the Black Gate caps is like 160db down.  This is frighteningly low....  If the resistor is noisy you are going to hear it clear as a bell ringing.  So far I don't hear any white noise reminiscent from my first build in the highest gain setting.  That is wonderful news for those owning very low LOMC in the 0.12 to 0.18 mv range. 

Mission accomplished.  So far so good. 
 

Bluesky,

Solder wick comes in different thickness and widths.  I like to use the number two size so it wicks up the solder smartly from the Clarinet and Cornet boards.  Send me a message with your address and I will send you a few ft of the stuff to evaluate.  Let me know.

Right now, from my listening seat, the PRP resistors are silly quiet.  I did some test recordings today so we will see how it stacks up abx style.

Cheers!