2 hours ago, jon96789 said:

When the crackling noise was happening, I tried reseating all the tubes... It did not affect the noise until it faded away...

 

I replaced all the tubes in the amp just now... So far, it is okay...

 

I talked to the tech who was working on my amp.  He said it's likely a cap issue.  It's  probably energizing after being fully discharged.  It is pointing to a bad cap.  

I have been following this forum for a while without contributing. Since 2022, I have had an R8. It is my first tube amplifier. I use PSvane KT88 tubes. The device sounds fantastic in combination with my self-built speakers featuring Lii-audio F12 drivers.

 

Some weeks ago, the V2 tube broke (red plated). In my search for a solution, I discovered this forum. What a wealth of information! I have since read all 600 pages!!! That took me a lot of time, but I had a great laugh at @Patrick. K. enthusiasm. His Frankenstein R8-device must sound amazing. My deepest thanks go to @SkunkieDesigns, whose knowledge videos have introduced me to a new hobby and provided the solution to my tube problem. I am currently halfway through her modifications.

 

I also enjoyed the discussion about the influence of the room in which you listen to music and how it affects the evaluation of internal modifications or tube swaps. I can definitely confirm this. In summer, I sometimes move my system to the lawn in the garden. There, the R8 and my speaker set have space without the influence of wall and ceiling reflections. The system sounds completely different there—so much better in my opinion—more spacious and less sharp.

I invite fellow music lovers for an enjoyable listening evening, and without exception, everyone is enthusiastic. So, if you have space in your garden and your neighbors don't mind, I can definitely recommend it! 

 

Once again, thanks to everyone who has contributed to this fantastic forum.

14 minutes ago, DeBreuk said:

I have been following this forum for a while without contributing. Since 2022, I have had an R8. It is my first tube amplifier. I use PSvane KT88 tubes. The device sounds fantastic in combination with my self-built speakers featuring Lii-audio F12 drivers.

 

Some weeks ago, the V2 tube broke (red plated). In my search for a solution, I discovered this forum. What a wealth of information! I have since read all 600 pages!!! That took me a lot of time, but I had a great laugh at @Patrick. K. enthusiasm. His Frankenstein R8-device must sound amazing. My deepest thanks go to @SkunkieDesigns, whose knowledge videos have introduced me to a new hobby and provided the solution to my tube problem. I am currently halfway through her modifications.

 

I also enjoyed the discussion about the influence of the room in which you listen to music and how it affects the evaluation of internal modifications or tube swaps. I can definitely confirm this. In summer, I sometimes move my system to the lawn in the garden. There, the R8 and my speaker set have space without the influence of wall and ceiling reflections. The system sounds completely different there—so much better in my opinion—more spacious and less sharp.

I invite fellow music lovers for an enjoyable listening evening, and without exception, everyone is enthusiastic. So, if you have space in your garden and your neighbors don't mind, I can definitely recommend it! 

 

Once again, thanks to everyone who has contributed to this fantastic forum.

You win for best room

27 minutes ago, DeBreuk said:

So, if you have space in your garden and your neighbors don't mind, I can definitely recommend it! 

 

It's good that you've the cage over the tubes as the bovine in the background may think the bottles are udders otherwise when the gear is left unattended. What do you do when it rains? What are the speakers? Lii-audio 10's or similar? It looks great. 👍

Edited February 14, 20251 yr by xlr8or

26 minutes ago, xlr8or said:

 

It's good that you've the cage over the tubes as the bovine in the background may think the bottles are udders otherwise when the gear is left unattended. What do you do when it rains? What are the speakers? Lii-audio 10's or similar? It looks great. 👍

 

This listening setup is temporary and highly dependent on the weather forecast. Although many modifications have been discussed on this forum, I have yet to come across a waterproof R8. The drivers are Fast 12's from Lii Audio.

5 minutes ago, DeBreuk said:

 

This listening setup is temporary and highly dependent on the weather forecast. Although many modifications have been discussed on this forum, I have yet to come across a waterproof R8. The drivers are Fast 12's from Lii Audio.

 

How are you finding the Fast 12's?

5 minutes ago, xlr8or said:

 

How are you finding the Fast 12's?

 

I don't have much experience in comparing sound systems, but the combination of the F12s in this enclosure together with the R8 suits me very well. The drivers aren't particularly dynamic, so don't expect high-end audio with speed metal 🤘🎸

@DeBreuk Hand down the best interior (exterior) design I have seen involved an R8. Have you try toe-in and move abit closer to the speakers? say 3 feet? Oh and welcome + kudos to reading 600+ pages.

On 14/02/2025 at 6:55 AM, jon96789 said:

When the crackling noise was happening, I tried reseating all the tubes... It did not affect the noise until it faded away...

 

I replaced all the tubes in the amp just now... So far, it is okay...

Jon, does it make crackling noise when volume is adjusted as well? if it does, clean and reseat your 6SL7. There's a possibility of cold soldering as well, I would reflow all the soldering on the 6SL7 sockets.

Edited February 14, 20251 yr by lulucas

I cleaned and reseated all the tubes, applying DeOxit as well... I had a tech resolder all the joints as well... No luck with that... Thanks, though.

11 hours ago, lulucas said:

@DeBreuk Hand down the best interior (exterior) design I have seen involved an R8. Have you try toe-in and move abit closer to the speakers? say 3 feet? Oh and welcome + kudos to reading 600+ pages.

 

I've done quite a bit of experimenting with an outdoor setup. Outdoors, I can turn up the volume on the R8 much further (upto 2 o’clock) without it sounding too loud or harsh. The limiting factor is the Lii-audio driverset not the R8. The drivers are very sensitive. 

The greater the distance between the speakers, the larger the sweet spot (up to 3 meters wide). I prefere a distance of 6 meters between the speakers (with an 8 meter distance to the chair). I angle the horn speakers slightly outward (toe-out).
 

14 hours ago, DeBreuk said:

 

I've done quite a bit of experimenting with an outdoor setup. Outdoors, I can turn up the volume on the R8 much further (upto 2 o’clock) without it sounding too loud or harsh. The limiting factor is the Lii-audio driverset not the R8. The drivers are very sensitive. 

The greater the distance between the speakers, the larger the sweet spot (up to 3 meters wide). I prefere a distance of 6 meters between the speakers (with an 8 meter distance to the chair). I angle the horn speakers slightly outward (toe-out).
 

I was thinking about distortion from cranking up the volume to accomodate the distance to seating position, but it seems you don't have any issues. I'm suprise that you can crank your volume to 2 o'clock and still sounds good, assuming your source is @2 vrms. I have never gone pass 11 o'clock so I can't really tell 🙂

Edited February 16, 20251 yr by lulucas

On 15/02/2025 at 11:18 AM, jon96789 said:

I cleaned and reseated all the tubes, applying DeOxit as well... I had a tech resolder all the joints as well... No luck with that... Thanks, though.

Sorry to hear that there's no conclusive fix for your R8, your seems to have really hard to troubleshoot issues for some reason. In regards to noisy volume pot at 12 o'clock, I reduced the noise further from previous state by replacing the wiring on the input jacks and added extra electrical tape between input and chassis. Noise is still there but barely audible, so my assumption is that there are multiple sources that generate noise when volume at 12 o'clock. I'm done with elimination process for this issue, can't think of anything else that I can try.

 

SOS !!!!!

Good morning, everyone! I need some help.
I've completed most of the modifications, but now, while measuring the voltage points, I'm seeing unexpected values (highlighted in red) at pins 2 and 5 of the 6SN7 on both channels. 😞
What could be causing this issue? Any insights would be greatly appreciated!

Mistaken post. 

   

Edited February 20, 20251 yr by jrethorst
mistake

If you cannot figure how to get the cover off, I suggest you get someone else to do the modifications for you.  

16 hours ago, maurods said:

 

SOS !!!!!

Good morning, everyone! I need some help.
I've completed most of the modifications, but now, while measuring the voltage points, I'm seeing unexpected values (highlighted in red) at pins 2 and 5 of the 6SN7 on both channels. 😞
What could be causing this issue? Any insights would be greatly appreciated!

<image removed by Fruit for brevity>

The voltage at the cathodes appears good indicating current draws of the triodes are good, but the voltages at the anodes appear lopsided.
Without having access to the unit nor precise voltage readings around the 6SL7's the above observations indicate, to me,  a non-zero voltage offset at the input. 
I would disconnect all inputs and ensure that the 220K and 1K at the 6SL7 are good and soldered properly.
Regards.

58 minutes ago, jon96789 said:

If you cannot figure how to get the cover off, I suggest you get someone else to do the modifications for you.  

 

Wise words!  👍

 

13 ore fa, Fruit ha detto:

La tensione ai catodi sembra buona indicando che i tiraggi di corrente dei triodi sono buoni, ma le tensioni agli anodi appaiono sbilanciate.
Senza avere accesso all'unità né letture di tensione precise intorno al 6SL7, le osservazioni di cui sopra indicano, per me, un offset di tensione diverso da zero all'ingresso.
Scollegarei tutti gli ingressi e mi assicurerei che il 220K e l'1K del 6SL7 siano buoni e saldati correttamente.
Saluti.

Good morning, and thank you for your valuable help!
I have checked the resistors, and they seem to be OK. Now, I have installed the original tubes and redone all the measurements, which I am attaching. I also have an issue with the BIAS meter, which fluctuates and is difficult to stabilize.

Thank you, I really need your help!

Best regards,
Mauro

@Mauro, any chance of an actual photo from inside the unit, we can't really know 100% which parts were replaced, this would make it easier for everyone to assist you.

There is a bit of discrepancy between left and right V of 330uf caps, 

 - Is it still original choke or Hammond? 

- Have you check for cold soldering? 

- Have you triple check all your grounding? 

With the erratic bias reading, could be faulty pot or tube, 

- Give the pot a few turns and see if that can be fix and also test it with different tube.

 

There seems to be multiple issues on your unit that needed to be tackle one at a time, I would suggest you to take break from the R8 for a day, clear your head and come back.

- Then check your soldering and reflow if needed ( I would just reflow everything)

- Tackle one issue at a time, confim your V readings for everything, test the unit and move on to the next outstanding issue.

 

9 ore fa, lulucas ha detto:

@Mauro, qualsiasi possibilità di una foto reale dall'interno dell'unità, non possiamo davvero sapere al 100% quali parti sono state sostituite, questo renderebbe più facile per tutti assisterti.

C'è un po' di discrepanza tra V sinistra e destra di 330uf caps,

- È ancora strozzatura originale o Hammond?

- Hai controllato la saldatura a freddo?

- Hai controllato tre volte tutto il tuo grounding?

Con la lettura irregolare dei pregiudizi, potrebbe essere un vaso o un tubo difettoso,

- Dai alla pentola qualche giro e vedi se può essere risolto e provalo anche con un tubo diverso.

 

Sembra che ci siano più problemi sulla tua unità che dovevano essere affrontati uno alla volta, ti suggerirei di fare una pausa dall'R8 per un giorno, liberare la testa e tornare.

- Quindi controlla la saldatura e il riflusso se necessario (io rifluirei tutto)

- Affronta un problema alla volta, conferma le tue letture V per tutto, testa l'unità e passa al prossimo problema in sospeso.

 

Good morning and thank you for your help. These are the components I have replaced:

330µF power supply capacitor with two Kemet 330µF 550V capacitors

Two capacitors on the transformer

The choke, replaced with a Hammond 194G

The four capacitors on the bias boards and added a safety resistor

Duplicated the circuit of the 6SL7 and brought the filament power supply to the center

Replaced the resistors on the EL34 sockets

Replaced the 0.33µF capacitors on the 6SL7

No modifications to the ground path

Thank you for your kindness.
Mauro

I picked up a set of RCA 6SN7 and 6SL7 "smoked glass" tubes... Popped them in my R8 and was disappointed to hear an emphasis in the warmth in the sound. The music just sounded too think and heavy with no top end. Then something struck me... I have a couple of quads of the Psvane EL34-PH Legend tubes.  I was not too enamored with the sound of these high-end EL34s from Psvane when paired with Sylvania tubes. There was no warmth and the top end was too hot for my tastes. I figured why not pair the RCAs with the Psvane EL34PH tubes together?  Sure enough, the sound came out more balanced.  The Psvane added some transient response as well, piano strokes, guitar strumming and percussion had better impact and sharpness. The hot top was tapered off and the warm bottom end was more balanced. This shows how synergy between tubes is so important. What may sound terrible in one combination may sound awesome in another.

1 hour ago, jon96789 said:

 This shows how synergy between tubes is so important. What may sound terrible in one combination may sound awesome in another.

Yup, hence a bloody expensive hobby at that. I also have a set of NOS RCA 5691 Red base incoming as well, should be very sweet with my reissue tungsol 6550 but will see

7 minutes ago, lulucas said:

Yup, hence a bloody expensive hobby at that. I also have a set of NOS RCA 5691 Red base incoming as well, should be very sweet with my reissue tungsol 6550 but will see

Those RCA 5691 are great sounding tubes. To my ears.