[tuatara]

Quote:

Originally Posted by minivan /img/forum/go_quote.gif i had been experiencing constant hum on the left channel lately on the yama. i happened to have isotropyl alcochol swab lying around, the one they use it to wipe your skin before the injection in the hospital. after i used it to clean the pin of the tube, all hum gone, and the sound seem to be a bit clearer too. the whole process only took a few minutes,, i had read about people having hum on their amp, and changing tube and power cord,etc. may be it's worth while to clean the pin of the tube first? well it is for my case.

Head of the class for this one minivan.
Having nothing better to do this afternoon I took the tubes from the Yamamoto, cleaned them with some isopropyl alcohol left over from my record cleaning brew, gave them a 2nd clean with some CRC contact cleaner and refitted.
Presto , first time since I've owned the amp(nearly a year) that I've had absolutely no hum.
The most sensitive phones have always been the AD2000s and now I can go to full volume with complete silence.
Am I happy??...

 

[JML]

There have been many posts elsewhere about using Flitz metal polish on all sorts of electrical contacts, followed by a treatment with something like Caig DeOxit or ProGold. It's possible that might be a good idea for tube pins (I don't have any tubed equipment, or I'd try it).

 

[Capunk]

Sorry to ask this, but has anyone here compare this amp to Darkvoice 337? is it in the same league?

 

[Superpredator]

Quote:

Originally Posted by Capunk /img/forum/go_quote.gif Sorry to ask this, but has anyone here compare this amp to Darkvoice 337? is it in the same league?

Having owned a 336i and listened to a 332 briefly at a meet I would say that, whether in the same league or not, the 337 is likely suited to different headphones. The Darkvoice line seems very Sennheiser-centric while the Yamamoto is soul mate to the AT woodie line. I doubt there is a single headphone you could use to accurately and fairly measure them against each other.

 

[Capunk]

From the moment I see the Yamamoto Pic, I already know this is will match well with Audio Technica (esp. W1000 - similar wood color), but I do believe some of yammy's owner pair it with K701, or other headphones. And DV337 is in *nearly* similar price range as HA-02, so I wanted to know, how's both amps performances when they're compared.

 

[tuatara]

Anyone who really wants to have a good go at cleaning tube pins there's an interesting read here
http://www.pearl-hifi.com/06_Lit_Arc...Your_Tubes.pdf

 

[Superpredator]

Quote:

Originally Posted by Capunk /img/forum/go_quote.gif From the moment I see the Yamamoto Pic, I already know this is will match well with Audio Technica (esp. W1000 - similar wood color), but I do believe some of yammy's owner pair it with K701, or other headphones. And DV337 is in *nearly* similar price range as HA-02, so I wanted to know, how's both amps performances when they're compared.

Gotcha. Actually using the K701 might be a good way to conduct a comparison of these two amps since neither is exactly suited to that headphone, IMO. The K701 sounded decent with the Yamamoto as well as the 336i (which I believe is similar in sound to the 337), but for Yamamoto or 337 money I think one could do better (the Cayin HA-1A, for example). Of course, I haven't heard the 337, so this is just a barely educated guess.

 

[tuatara]

Quote:

Originally Posted by Superpredator /img/forum/go_quote.gif Gotcha. Actually using the K701 might be a good way to conduct a comparison of these two amps since neither is exactly suited to that headphone, IMO. The K701 sounded decent with the Yamamoto as well as the 336i (which I believe is similar in sound to the 337), but for Yamamoto or 337 money I think one could do better (the Cayin HA-1A, for example). Of course, I haven't heard the 337, so this is just a barely educated guess.

I wasn't overly impressed with the 701/Yamamoto combo, just seemed a bit dry and sterile for my tastes, although I didn't like the AKG with any of my amps and eventually sold it.

 

[kugino]

Quote:

Originally Posted by tuatara /img/forum/go_quote.gif I wasn't overly impressed with the 701/Yamamoto combo, just seemed a bit dry and sterile for my tastes, although I didn't like the AKG with any of my amps and eventually sold it.

i actually liked the k701/yamamoto pairing as the yamamoto gave the k701 some midrange boost and a bit of warmth as well. i've not heard the k701 with any of the darkvoice amps so can't provide a comparison...but i think i liked the k701 better out of the yamamoto than, say, the GS-1.

 

[Gav]

Quote:

Originally Posted by minivan /img/forum/go_quote.gif i had been experiencing constant hum on the left channel lately on the yama. i happened to have isotropyl alcochol swab lying around, the one they use it to wipe your skin before the injection in the hospital. after i used it to clean the pin of the tube, all hum gone, and the sound seem to be a bit clearer too. the whole process only took a few minutes,, i had read about people having hum on their amp, and changing tube and power cord,etc. may be it's worth while to clean the pin of the tube first? well it is for my case.

That is a great tip its somthing that I would never of thought of

 

[silmaauki]

I have loaned this amp from a local dealer for a few days. I am looking for a new amp for my RS-1. So far this amp sounds better than anything I have tried so far - I haven't tried many. I am pleased with this amp, but the hum DOES irritate me too.

In the first place my MingDa MC66-AE did create a lot of hum when it was turned on and located next to HA-02. Power off did help a little, but still the presence off MingDa (power cord was connected) created some hum. Well, I removed the MingDa totally from the same desk. This helped again a lot, but still some hum existed. I tried to clean the pins of the tubes but it didn't help at all. Let's say that the hum didn't bother me all the time but with some chorus works and classical music it DID bother me. The latest trick I did was removing and reattaching the power plug (turned the phase). Now it sounds like the hum is gone. I am just wondering if it stays away (I couldn't recreate the hum by turning the phase back to "original")

Another thing that I am not very pleased with this Yamamoto is the balance (of the volume pot).

Though, the sound is awesome. I don't know if I should buy this or not.

 

[kugino]

Quote:

Originally Posted by silmaauki /img/forum/go_quote.gif I have loaned this amp from a local dealer for a few days. I am looking for a new amp for my RS-1. So far this amp sounds better than anything I have tried so far - I haven't tried many. I am pleased with this amp, but the hum DOES irritate me too. Another thing that I am not very pleased with this Yamamoto is the balance (of the volume pot). Though, the sound is awesome. I don't know if I should buy this or not.

i haven't had any hum problems except with the most sensitive of my headphones...but at low volumes there are some channel imbalance issues. they go away once the volume is raised to normal listening levels, but i'd like to see a better pot being used in this amp. granted, it's only there at very low listening levels, but it does bother me a bit that it's there at all.

 

[slwiser]

Quote:

Originally Posted by silmaauki /img/forum/go_quote.gif Another thing that I am not very pleased with this Yamamoto is the balance (of the volume pot). Though, the sound is awesome. I don't know if I should buy this or not.

The volume imbalance can come into play with mine if I tend to overdrive it with to much voltage coming in. Then I don't have enough turn-down ratio from loud to quite music available. I tend to keep my Lavry set around 35 so the voltage is going to be around 1v rms into my Yamamoto. This allows me to turn the Yamamoto up to near noon position for some tracks.

 

[tuatara]

Haven't noticed an imbalance with mine, normally set around 8, never more than 9 oclock.
Is this more likely to be an issue with pc/i-pod source against cdp or TT?

 

[silmaauki]

My source has been Meridian 506. Normal listening volumes are around 8-9.

When pot is turned fully left, the right channel is totally quiet (as it should be) and the right channel is "quite" loud (it shouldn't be). There are some minor balance problems elsewhere as well. Not good at all!

The hum with this unit is strange. Someone else has reported that it comes and goes. This unit performs likewise. Besides quite often touching the unit does either strengten or lower the hum. Sometimes there is no effect.

Though is sounds lovely.