resistors

stvnharr · « **on:** 18 Jul 2003, 08:07 pm »

With Black Gate caps being all the talk of tweak these past few days, I was wondering if there are opportunities for resistor tweaks at suitable places in the Aksa 55. There are lots of fancy resistors out there, does anyone have any experiences with them?

Malcolm Fear · « **Reply #1 on:** 18 Jul 2003, 10:12 pm »

Funny you should mention.
I stuck a cheap metal film resistor in the signal path of my GK-1. I then had the opportunity recently to hear a Riken Ohm carbon film resistor (thanks John R). They are not cheap (a couple of bucks compared to a couple of cents for Rat Shack metal film). They are very swish, pure copper leads, gold plated.
It made the GK-1 sound very very nice (as opposed to very nice). It relaxed the sound, more mellifluous (I love that word). I have ordered more. I am going to replace all resistors in the signal path in the GK-1 and AKSA 55.
I will report back under the Valhalla headings (in a few weeks).

stvnharr · « **Reply #2 on:** 18 Jul 2003, 10:53 pm »

Malcolm,
I've been looking at the Riken's as well. Which resistors in the 55 are you thinking of replacing? In the direct signal path, I only see R9, but others are close. Where would one logically stop?

Malcolm Fear · « **Reply #3 on:** 18 Jul 2003, 11:44 pm »

Hi stvnharr
Yep, I am just going to try R9. I figure (rightly or wrongly) that the ones to earmark for upgrade, are those directly in the signal path.

Perhaps Hugh could enlighten more?

BTW, Riken Ohm can be got at
http://www.angela.com
and
http://www.partsconnexion.com/
Parts Connection are cheaper, with no minimum order, and they have good prices on Blackgates.

stvnharr · « **Reply #4 on:** 19 Jul 2003, 04:34 am »

Did a search on audioasylum and found the following on changing resistors
http://db.audioasylum.com/cgi/m.pl?forum=tweaks&n=36242&highlight=riken&session=

Maybe the resistor idea won't amount to much.

doug s. · « **Reply #5 on:** 19 Jul 2003, 11:45 pm »

dunno about the aksa, but the riken-ohms were better than the holco's in my modded art di/o... sweeter, w/no loss of resolution.

doug s.

AKSA · « **Reply #6 on:** 20 Jul 2003, 02:13 am »

Hi Mal, Steven,

I won't say too much about resistors because I haven't tried many different types. I do believe that caps make the most different to amp sonics.

Suffice to say a good quality metal film, like the German Beyschlags, is a very good resistor, which adds clarity and sharpness to the sound.

The resistors of sonic importance on the AKSA 55W are as follows (in decreasing order of influence):

R9, R13, R14, R16, R17, R1, R4.

Rikenohm should be fine. Do not fit wire wound resistors to R13/14/16/17. This could cause the amp to go burlesque......

Cheers,

Hugh

Cheers,

Hugh

mgalusha · « **Reply #7 on:** 20 Jul 2003, 04:03 am »

Not AKSA specific but perhaps relevant - I recently built a tube phono preamp and it wasn't as quiet as specified. I had to substitute 1 resistor per channel from the part specified because it was out of stock. Several days ago I received the back order and swapped in the new resistors with little hope they would make any difference. Both were inexpensive metal film types. Imagine my surprise (and delight) when the signal to noise ratio improved by a whopping 18dB.

What was an excellent sounding but noisy preamp was now excellent sounding and quiet. Obviously the first stage of a phono preamp is a high gain and noise sensitive environment while a power amp or preamp should not be as sensitive. I never put a lot of money into boutique resistors thinking a standard metal film should get the job done. My experience this week was certainly eye opening.

Mike

Malcolm Fear · « **Reply #8 on:** 20 Jul 2003, 04:54 am »

Hi Mgalusha

I believe that carbon film are very good sounding, but are noisy. This doesn't matter in a pre amp, but they shouldn't be used in a phono stage.
I used Dale/Vishay metal film in my AKSA GK-1 phono section. They sound great.

stvnharr · « **Reply #9 on:** 20 Jul 2003, 05:01 am »

Oh my, carbon film, metal film, and the others - how to choose?
Hugh is certainly correct in capacitors being much more critical and likely to bring improvement. Thanks Hugh for the priority of resistors to go for.

mgalusha · « **Reply #10 on:** 20 Jul 2003, 01:21 pm »

Hello Malcolm,

Actually both were metal film types, that is why I was so suprised at the difference in noise.

Malcolm Fear · « **Reply #11 on:** 20 Jul 2003, 03:04 pm »

Sorry. I've got to read more carefully.
Strange how 2 different metal films are different in noise!
What brands were the noisy and quiet resistors?

mgalusha · « **Reply #12 on:** 20 Jul 2003, 05:30 pm »

Malcolm,

The quiet ones are Xicon (purchased from Mouser) and the noisy one's were "BC Components" purchased from Digikey. I was extremely surprised that a supposedly equivalent part was so different. I had examined my construction repeatedly looking for mistakes that would account for the noise and could find none.

I was going to try some different coupling capacitors in hopes that would improve the SN ratio. Speaking with a friend he mentioned how much trouble another friend had getting quiet enough resistors for the first stage of his phono section. I looked at the schematic and noticed the only resistor I had substituted from spec was in the first stage. Since the correct parts had arrived the previous day, I had nothing to lose but a few minutes to swap them out. It certainly drove home the point that not all parts are created equal.

Mike

andyr · « **Reply #13 on:** 23 Nov 2003, 12:09 am »

Quote from: Malcolm Fear

Hi Mgalusha

I used Dale/Vishay metal film in my AKSA GK-1 phono section. They sound great.

Malcolm, hi.

I'm just starting to build my GK-1 so I've been reading all the relevant posts.
1. Can U pls explain why you decided to use Dale/Vishay reses in the phono stage?
2. What improvement do you think they deliver over Hugh's Beyschlags?
3. Is this not a place for the good ol' Riken Ohms?

Thanks,

Andy

Raj · « **Reply #14 on:** 23 Nov 2003, 10:42 am »

Hi Guys,

I've tried a few resistors over the last couple of weeks in the signal path,

audio note tantalums = smooth mellow sound, personally I don't like them, you loose far too much resolution and I think they are noisy, space between instruments dissapears. Okay for perhaps just one position in the siganl path and not for an entire topology.

Welwyn rc55y = much better than ordinary metal films and the tanatlums and cheaper too! Bringing better seperation and tone to music, and also nice vocals, in my opinion the best bang for buck in metal films, you can now get these from farnell at around 70-80 pence each. Worth a try at least, even if you are looking for smooth sound ala carbon types, at least try these in the feedback loops or every where, if you have too much detail combine with tanatlums or carbon types to get a mix..............

I haven't tried carbon films cause I like the welwyn so much, I like my sytem to be detailed but also smooth and expansive. Obviously it's a matter of taste.....

Thanks
Raja