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Edited July 22, 20214 yr by muon*

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Edited July 22, 20214 yr by muon*

6 minutes ago, muon* said:

Just keep the cap away from sources of EMI/RFI, like some wiring.

 

Keep leads as short as possible and the twisted pair of 0.8mm lead out likely won't fit through the PCB holes that the leads on the stock caps pass through, but can be inventive and snip about 8mm to 1mm off one of the twisted pairs at the ends and just past the longer one through if it can and bend on the underside hard against the eyelet and solder, solder the lead where it was sniped above also.

 

The outer foil ends of these caps are marked, install with the outer foil end to the previous section (lowest impedance side).

 

I think caps will fit on the pcb itself. Only thing is one lead will have to be taken down from below cap to pcb and caps needs to be glued to pcb. Thanks for suggesting these good and reasonably priced caps.

@muon* Do you reckon to replace only coupling caps or Grid leak one shall also be replaced with your experience?

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Edited July 22, 20214 yr by muon*

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Edited July 22, 20214 yr by muon*

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Edited July 22, 20214 yr by muon*

I trust Queenslanders ? and just placed order for 4 caps with express shipping 

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Edited July 22, 20214 yr by muon*

Watching this with high interest post cap upgrade.

Great work guys.

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Edited July 22, 20214 yr by muon*

@Atmaj Can you tell me what vintage and type of Sylvania 6SL7 you were using? Your comment regarding the TS 6SU7WGT being brighter, by comparison, has me intrigued. I think I might add a pair of Sylvanias to the arsenal...

11 hours ago, muon* said:

Whether or not anyone proscribes to burn in/run in with caps, I's suggest not giving caps like these Miflex ones a final verdict until they have plenty of hour up on them, will sound better from the get go but will improve over the initial first 100 hours of use.

 

Edit: they will open up more and bass will improve with initial use.

Yup, breaking in applies to caps as well. Specifically PIO would take bit longer.

1 hour ago, echorec said:

@Atmaj Can you tell me what vintage and type of Sylvania 6SL7 you were using? Your comment regarding the TS 6SU7WGT being brighter, by comparison, has me intrigued. I think I might add a pair of Sylvanias to the arsenal...

I am using Sylvania 6SL7 GT side gator which has clear top and gray side glass. Prior to this, I tried PHILIPS ECG 5691 JAN as well. This tube was also good but it was missing dynamics, everything was compressed. Sylvania has a great balance, cleanliness and slightly rolled off but sparkle at the top end.

 

TS 6SU7WGT is also a great tube but it has more focused mids (bit higher mids) than Sylvania hence I did not like. Again, everything depends upon what other tubes you have in your amp, what speakers you have and most importantly your own preference.

 

If you are a mid loving person, you will like TS 6SU7WGT over Sylvania and TS EL34 as well as power tubes.

Following the cap replacement with interest.  I have the Willsenton R-35i.  The amp, with different tubes, is amazing, but I would consider replacing caps if the difference is significant.  I did this on the crossover of some speakers I built from kit and the difference was easily noticeable.

Hi 

saw a review on you tube and seems like it’s getting good reviews 

just wondering how I would fit this in to my system 

Can it be used as a pre amp or would I be better using it as an integrated and would it run my acoustic research AR90 

cheers for any advice 

 

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Edited July 22, 20214 yr by muon*

Well, again, I couldn't resist - I ordered a matched pair of the famed NOS RCA Red Base 5691 to hear how they perform in the R8. I figure it will be nice to have a pair of these in the collection for future amps anyways as they seem to be getting a little more scarce/expensive with each passing year. Should have them in about a week and will report some first impressions.

10 hours ago, Sean Perth said:

Hi 

saw a review on you tube and seems like it’s getting good reviews 

just wondering how I would fit this in to my system 

Can it be used as a pre amp or would I be better using it as an integrated and would it run my acoustic research AR90 

cheers for any advice 

 

if you looking for a tube pre , have a look at musical paradise MP701, very versatile and sounds great out of the box.

 

https://www.musicalparadise.ca/store/index.php?route=product/product&product_id=103

Edited November 19, 20205 yr by demoiree

5 hours ago, demoiree said:

if you looking for a tube pre , have a look at musical paradise MP701, very versatile and sounds great out of the box.

 

https://www.musicalparadise.ca/store/index.php?route=product/product&product_id=103

Thanks will look at that

 

On 11/11/2020 at 5:48 PM, echorec said:

I received the replacement part from Yong yesterday! Instead of sending a potentiometer, he sent me the entire populated bias circuit board with leads attached, so I was quite pleased. I took the amp into my local HiFi shop yesterday and was able to pick it up this morning. Everything sounds good, so hopefully the problem doesn't come up again. I kept the old bias PCB in case I need any of those parts later. The labor cost to replace the bias circuit and bench test was $125 USD, so my R8's cost definitely went up. Still better than having to ship this beast to someone elsewhere and deal with that whole headache. A word of advice: if you have any issues with your amp, be patient with Yong. I think he is absolutely slammed with emails each day. He will get back to you and he will help you make things right, but sometimes he isn't as responsive as many of us are used to. I read somewhere else that he has apparently hired some people to help him, so that is good news if true.

 

A couple of interesting comments from the service guy (This is one of the best guys in our State. He's been building and servicing tube amps for a very long time and works with a lot of high level and boutique HiFi equipment). His first comment was how he thought the design and layout was really good on this amp. He told me the solder job was "a bit sloppy" as he had to touch up several spots inside the amp that could have potentially turned into future problems. His final comment was that he thought the amp sounded "very beautiful and musical".

ecohrec, 

I'm really glad things workout for you. I just purchased a unit and your story gave me some concerns. I know is a electrical/mechanical device and problems will come up, is just that dealing with the supplier so far away. But, lots of good comments and info on this website. 

 

Peace,

Tony

Been following this thread with interest. 

 

I have the Willsenton R-35i  and had been considering one of their 300B models.  The cost of 300B tubes has slowed me down however and I am now thinking about getting an R8 to play with.  Yong said in an e-mail yesterday that he can have a unit shipped 7 business days after I order it.  That sounded too good to me so I asked him for confirmation.  If he confirms, I will probably order a unit with the Willsenton KT88 tubes.  I'll then try some tube rolling with the 6SL7s and two of the 6SN7s.

On 19/11/2020 at 8:33 AM, Atmaj said:

I am using Sylvania 6SL7 GT side gator which has clear top and gray side glass. Prior to this, I tried PHILIPS ECG 5691 JAN as well. This tube was also good but it was missing dynamics, everything was compressed. Sylvania has a great balance, cleanliness and slightly rolled off but sparkle at the top end.

 

TS 6SU7WGT is also a great tube but it has more focused mids (bit higher mids) than Sylvania hence I did not like. Again, everything depends upon what other tubes you have in your amp, what speakers you have and most importantly your own preference.

 

If you are a mid loving person, you will like TS 6SU7WGT over Sylvania and TS EL34 as well as power tubes.

 

On 20/11/2020 at 6:16 AM, echorec said:

Well, again, I couldn't resist - I ordered a matched pair of the famed NOS RCA Red Base 5691 to hear how they perform in the R8. I figure it will be nice to have a pair of these in the collection for future amps anyways as they seem to be getting a little more scarce/expensive with each passing year. Should have them in about a week and will report some first impressions.

 

You guys should also consider giving the ECC35 a try. The very late 1940's or early 1950's  black or brown base 1347 coded or later mid to late 1950's brown base RU1, RU2, RU3 or RU4 coded straight bottle types made in the Blackburn UK factory sound really awesome. The Tung-Sol black coated glass brown base 1950's 6SU7GTY tube is also very good but in second place compared to the ECC35 above.

Edited November 20, 20205 yr by xlr8or

3 hours ago, chinook9 said:

Been following this thread with interest. 

 

I have the Willsenton R-35i  and had been considering one of their 300B models.  The cost of 300B tubes has slowed me down however and I am now thinking about getting an R8 to play with.  Yong said in an e-mail yesterday that he can have a unit shipped 7 business days after I order it.  That sounded too good to me so I asked him for confirmation.  If he confirms, I will probably order a unit with the Willsenton KT88 tubes.  I'll then try some tube rolling with the 6SL7s and two of the 6SN7s.

 

That's great! I'm toying with the idea of adding that Willsenton 300b to the arsenal as it would be fun to compare it to the R8. Hard to beat that price for a decent SET. Btw, did you see the weight of that thing?? It's weighs as much as two R8s!

 

42 minutes ago, xlr8or said:

 

 

You guys should also consider giving the ECC35 a try. The very late 1940's or early 1950's  black or brown base 1347 coded or later mid to late 1950's brown base RU1, RU2, RU3 or RU4 coded straight bottle types made in the Blackburn UK factory sound really awesome. The Tung-Sol black coated glass brown base 1950's 6SU7GTY tube is also very good but in second place compared to the ECC35 above.

 

Thanks for the reco! A pair of ECC35's is one the short list. Either Mullards or Phillips Holland, though they are getting really pricey. Currently using TS black glass 6SU7GTY, which are my favorite so far. But I still feel like I want to relax those highs a tad more, hence the RCA Red Base for the next round.

5 minutes ago, echorec said:

 

That's great! I'm toying with the idea of adding that Willsenton 300b to the arsenal as it would be fun to compare it to the R8. Hard to beat that price for a decent SET. Btw, did you see the weight of that thing?? It's weighs as much as two R8s!

 

 

I would have to go with the R-300B model due to the weight.  Its 32Kg and I'm too old for heavy amps.  I have Tekton Electrons which are 92db efficient but at 4 ohms the 8 watts of the 300b might not do it so I'm thinking about the R8.  Everyone reports great success with the R8 and I think  I could  enjoy tube rolling the R8 and trying the KT88 and maybe 6550 tubes.  I have new production Mullard EL34s in R-35i.  It sounds great