Great work Skunkie. That 6SN7 voltage stabilizer is pretty interesting. I was looking at a Willsenton R300B I think it was, it seems that power supply is split rail too with two separate rectifiers.
I looked up the "exchange of ideas" or the text traffic on audiokarma regarding the 6SN7 voltage stabilizer. I understand now what's going on. It's important to understand, in my mind, the difference between that and a voltage regulator that holds voltage constant according to load.
Great video Steph ! Looking over the BOM for this project I don't see any wattage values for the resistors listed. Can you tell me what wattage they should be ? Thank you !
Wicked handy to have that open pad... wow... Instead of terminal strips, i low-key want to order a bunch of purple PCBs to use... hrrrmm.... As for "Operation" LOL, solder with power applied!
Thanks Skunkie! This looks neat! Please when you tell us your opinion about how the amp sounds after this mod, please indicate if it changes the character of the sound, I have a stock R8 and I like how it sounds. Cheers
@@SkunkieDesignsElectronics Thanks. Audio Note doesn't seem to make electrolytic caps in 33uf. Is there anything you'd recommend as a step up or two from Nichicon?
Mine is 150k on the diagram is 220k series with 39ohm. Should i replace the 150k would this increase or decrease my voltage? Currently is 224v after the mod thanks
@@SkunkieDesignsElectronics that's what makes it interesting and cool! I was imagining you taking speakers turntable or CD player and perform modifications to make it sound great! Just wondering if you upgrade other equipment in the hobby. Thank you.
Seems the schematic has wrong values in 2 places, first this 2x 3,3K weren't they suppose to be 5,6K after mod?, and in neg bias it should be 4,7K not 5,7K right?
That resistor in the neg bias is color banded and measures 5.7K which is a weird value. I ended up replacing it with a 5.6K and I drew up that one schematic as an example before I got in there working on it just to show what my idea was for the video. Once I get finished, I have to draw up final schematics and a BOM, which I'm sure people will find errors in :)
Curious if you think there could be any benefit to using (probably huge) film caps in any of those 33uf positions, particularly the two that used to be one 10uf. In the other video I believe you said one of the caps (on the voltage divider) needs to be slow to control the inrush, so I assume not that one!
Possibly there could be an audible difference, but you can get the same "effect" bypassing them with something around a .33uf film cap. As I have said, sometimes that improves things, sometimes it makes the amp sound shrill and brittle. And it's not that that one cap needs to be slow to control the timing on the voltage on the grid, that is set by the resistor value feeding it (150k) and the size of the cap. It's job after than is to stabilize the voltage there, help remove any residual ripple and also shunt any AC noise to ground.
@@SkunkieDesignsElectronics I noticed a definite difference. I used copper foil caps. I know $$. Others have stated audible difference with Mundorf and other caps.
Hi Stephe. Is it normal that capacitors from other manufacturers are much longer and larger? The original ones are 2cm long (350 and 450V), while those from other manufacturers are usually 3cm (350V) and 4cm (500V). Nichicons also have larger dimensions?
@@SkunkieDesignsElectronics Thank you for your answer. Unfortunately, in my country only larger sizes of capacitors are available (3, 4 cm). They may be, or is it better to wait longer and order smaller sizes from abroad?
@@SkunkieDesignsElectronics Thank you for your response. Unfortunately, I'll have to play around with this. I don't know what happened, but it's currently difficult to buy branded 33uf 350V axial capacitors in Europe. As if suddenly manufacturers stopped producing them. PS. Ok, noob here. Something touched me and I looked at your video again. Of course, it turned out that I made a mistake and realized that the capacitor should be radial and not axial. I have no idea why I insisted on this axial from the beginning. It's good that the matter was clarified before placing the order.
@@SkunkieDesignsElectronics Sorry, but I have one more question. Have you checked how many milliamps the amplifier delivers when the bias meter is in the middle? Are the values correct for EL34 and KT88? I'm curious whether the values aren't actually too low or too high. Unfortunately, the bias indicator is a very conventional system that does not say anything specific.
With that spare connection point available, it almost seems that Willsenton was planning on having a dual rail power supply until the accountants asked them to save another 10 cents on production costs.🙄
That mod turned out great! Everything looks factory, very neat and tidy. Looking forward to hearing your listening impressions.
Super looking mod. It will be interesting to know what you hear from the change....
Great work Skunkie. That 6SN7 voltage stabilizer is pretty interesting. I was looking at a Willsenton R300B I think it was, it seems that power supply is split rail too with two separate rectifiers.
I have seen that design in some amps, it's a good idea!
I looked up the "exchange of ideas" or the text traffic on audiokarma regarding the 6SN7 voltage stabilizer. I understand now what's going on. It's important to understand, in my mind, the difference between that and a voltage regulator that holds voltage constant according to load.
Woohoo! Thanks for another great mod video!
Love the close-up Stephe. At 06:51 I subconsciously blew at the screen trying to get the solder to solidify faster 😅
HA!
I was trying to pick the blob of solder spray from the yellow wire at 5:48
Nice comment about bypassing electrolytic capacitors...........came to the same observations as you did !
Yeah, while it can change the sound, it's not always an improvement!
Great video Stephe
Skunkie: basic :what is the benefit of better capacitors?
In this part I am upsizing the caps to help stabilize the current needs and also using the appropriate voltage ratings,
Great video Steph ! Looking over the BOM for this project I don't see any wattage values for the resistors listed. Can you tell me what wattage they should be ? Thank you !
Most are 2W, the two large ones on the front end are 3W and the 1 ohm cathode resistors on the power tubes are 1W.
Thanks Steph !@@SkunkieDesignsElectronics
Wicked handy to have that open pad... wow...
Instead of terminal strips, i low-key want to order a bunch of purple PCBs to use... hrrrmm....
As for "Operation" LOL, solder with power applied!
LOL!! Yeah no, not doing that :P
Thanks Skunkie! This looks neat! Please when you tell us your opinion about how the amp sounds after this mod, please indicate if it changes the character of the sound, I have a stock R8 and I like how it sounds. Cheers
On first listen, I feel like it added some sparkle/airiness. Sorta that veil lifting effect. Also the bass is tighter, I like it.
Those red resistors look like metalloxcide. If you shared that info I missed it.
The red resistors are the new metal film ones, Vishay PRO series. The gray ones I am removing are metal oxide.
@@SkunkieDesignsElectronics thank you for clearing that up and I enjoy your shows on MODS.
can i put 2pcs same 33uf 500v x2 yes? because one small one big , i prefer both be same size..?!..
Sure
can be 2pcs 450v there? or must 500v?
I can only find 1w resistors for the 2.2k position. Is that okay or should I wait for 2w?
Or use some 2K ones. that value isn't super critical.
@@SkunkieDesignsElectronics Thanks.
Audio Note doesn't seem to make electrolytic caps in 33uf. Is there anything you'd recommend as a step up or two from Nichicon?
Mine is 150k on the diagram is 220k series with 39ohm. Should i replace the 150k would this increase or decrease my voltage? Currently is 224v after the mod thanks
220k pretty sure would raise the voltage, and might get you closer to the 250ish volts I had.
Show us your equipment! What type of speakers, turntable, CD player, streamer, interconnects, speaker cables, etc...
It's nothing real special...
@@SkunkieDesignsElectronics that's what makes it interesting and cool! I was imagining you taking speakers turntable or CD player and perform modifications to make it sound great! Just wondering if you upgrade other equipment in the hobby. Thank you.
Seems the schematic has wrong values in 2 places, first this 2x 3,3K weren't they suppose to be 5,6K after mod?, and in neg bias it should be 4,7K not 5,7K right?
That resistor in the neg bias is color banded and measures 5.7K which is a weird value. I ended up replacing it with a 5.6K and I drew up that one schematic as an example before I got in there working on it just to show what my idea was for the video. Once I get finished, I have to draw up final schematics and a BOM, which I'm sure people will find errors in :)
Curious if you think there could be any benefit to using (probably huge) film caps in any of those 33uf positions, particularly the two that used to be one 10uf. In the other video I believe you said one of the caps (on the voltage divider) needs to be slow to control the inrush, so I assume not that one!
Possibly there could be an audible difference, but you can get the same "effect" bypassing them with something around a .33uf film cap. As I have said, sometimes that improves things, sometimes it makes the amp sound shrill and brittle. And it's not that that one cap needs to be slow to control the timing on the voltage on the grid, that is set by the resistor value feeding it (150k) and the size of the cap. It's job after than is to stabilize the voltage there, help remove any residual ripple and also shunt any AC noise to ground.
@@SkunkieDesignsElectronics I noticed a definite difference. I used copper foil caps. I know $$. Others have stated audible difference with Mundorf and other caps.
@@MrAroundsound You did this mod and then bypassed the new 33uf caps with .33uf copper foils?
Hi Stephe. Is it normal that capacitors from other manufacturers are much longer and larger? The original ones are 2cm long (350 and 450V), while those from other manufacturers are usually 3cm (350V) and 4cm (500V). Nichicons also have larger dimensions?
Caps are made in a wide variety if shapes and sizes. So yeah you will see a variety of sizes with the same specs.
@@SkunkieDesignsElectronics Thank you for your answer. Unfortunately, in my country only larger sizes of capacitors are available (3, 4 cm). They may be, or is it better to wait longer and order smaller sizes from abroad?
If there is space, the physical size doesn't matter. Just make sure the uf and the voltage is correct.
@@SkunkieDesignsElectronics
Thank you for your response. Unfortunately, I'll have to play around with this. I don't know what happened, but it's currently difficult to buy branded 33uf 350V axial capacitors in Europe. As if suddenly manufacturers stopped producing them.
PS.
Ok, noob here. Something touched me and I looked at your video again. Of course, it turned out that I made a mistake and realized that the capacitor should be radial and not axial. I have no idea why I insisted on this axial from the beginning. It's good that the matter was clarified before placing the order.
@@SkunkieDesignsElectronics Sorry, but I have one more question. Have you checked how many milliamps the amplifier delivers when the bias meter is in the middle? Are the values correct for EL34 and KT88? I'm curious whether the values aren't actually too low or too high. Unfortunately, the bias indicator is a very conventional system that does not say anything specific.
With that spare connection point available, it almost seems that Willsenton was planning on having a dual rail power supply until the accountants asked them to save another 10 cents on production costs.🙄