Dennis Had Inspire Amps

[khashmi]

Thanks Isaacc7, the KT-88’s have truly surprised me with their bass energy in my rig (Klipsch RP-8000f speakers). I tried both with the Freya tube and passive, but the passive sounded a bit anemic. Logged in 60 hrs so far. Plan is to get to 100 by next weekend.

Dennis shipped it with the Nos GE 5U4G rectifier, which is what I plan to use with the Pope 6V6 later this week. I’ve been researching alternative rectifiers and was eying the Sophia 274b mesh plate that a lot of members in this thread recommended but it’s bit expensive new, so looking for a good used deal. I’ll look up the 5w4.

As far as output tubes are concerned, I also plan to get the GL KT77 as they have some really good reviews in and out of this forum. Assuming my 5U4G rectifier will suffice for that as well.

[Isaacc7]

Originally Posted by khashmi

Thanks Isaacc7, the KT-88’s have truly surprised me with their bass energy in my rig (Klipsch RP-8000f speakers). I tried both with the Freya tube and passive, but the passive sounded a bit anemic. Logged in 60 hrs so far. Plan is to get to 100 by next weekend.

Dennis shipped it with the Nos GE 5U4G rectifier, which is what I plan to use with the Pope 6V6 later this week. I’ve been researching alternative rectifiers and was eying the Sophia 274b mesh plate that a lot of members in this thread recommended but it’s bit expensive new, so looking for a good used deal. I’ll look up the 5w4.

As far as output tubes are concerned, I also plan to get the GL KT77 as they have some really good reviews in and out of this forum. Assuming my 5U4G rectifier will suffice for that as well.

I have used an RCA 5u4g and an RCA 5y3 to good effect with my 6v6 tubes. Actually mostly listen to Jan 7c5 but I have some later Sylvania and some Ken Rad as well. All sound really good. Trying to figure out if the 5w4 drops more or less voltage than a 5y3.

[nhparrot]

Originally Posted by Isaacc7

I have used an RCA 5u4g and an RCA 5y3 to good effect with my 6v6 tubes. Actually mostly listen to Jan 7c5 but I have some later Sylvania and some Ken Rad as well. All sound really good. Trying to figure out if the 5w4 drops more or less voltage than a 5y3.

The 5W4 tube is a lower power version of the 5Y3. It uses less power
so it runs cooler and lasts longer, but it may not work in all circuits
due to the lower plate current rating.

The 5W4 has a Vdrop of 45, Compared to a 5Y3 with a Vdrop of 60

http://www.fourwater.com/files/fullrect.txt

[khashmi]

On the subject of rectifiers, I was reading earlier in the thread that it didn’t make much difference for folks with the IIPS mod? Is that something standard now since it was introduced? Trying to understand where I should spend my time and money in terms of rolling. For example yesterday I spent sometime reading up on the famed Mullard GZ34 rectifier. My takeaway was that it is almost universally beloved and lasts a lifetime. So, my question is if rectifiers don’t really make a big difference, should I focus my rolling dollars on output and input tubes and just leave the GE 5U4G be or is there something to getting a rectifier of each type, 5A4/GZ34, 5Y3, Sophia 274b mesh plate depending on the output tubes I may be using?

[Isaacc7]

Originally Posted by khashmi

On the subject of rectifiers, I was reading earlier in the thread that it didn’t make much difference for folks with the IIPS mod? Is that something standard now since it was introduced? Trying to understand where I should spend my time and money in terms of rolling. For example yesterday I spent sometime reading up on the famed Mullard GZ34 rectifier. My takeaway was that it is almost universally beloved and lasts a lifetime. So, my question is if rectifiers don’t really make a big difference, should I focus my rolling dollars on output and input tubes and just leave the GE 5U4G be or is there something to getting a rectifier of each type, 5A4/GZ34, 5Y3, Sophia 274b mesh plate depending on the output tubes I may be using?

I have resisted rolling different rectifiers other than to get the right amount of voltage to the anodes of the output tubes. In theory, the diodes in a rectifier in combination with capacitance and a choke should result in pure DC. In other words, if the rectifier is doing its job it should not be adding any sound (AC) at all to the signal. As a matter of fact I would bet that the other parts of the power supply have more to do with making pure DC power than the rectifier. It's my understanding that all a rectifier can do is take the AC and charge a capacitor with pulses of DC. The capacitor is what actually supplies the system with constant DC. Or do I completely misunderstand power supplies?

Setting aside things like longevity and adherence to specifications I have always chalked up audiophile worship of tube rectifiers to not understanding what they do. Maybe they really do make a difference and I don't understand what they do?

[Isaacc7]

Originally Posted by nhparrot

The 5W4 tube is a lower power version of the 5Y3. It uses less power
so it runs cooler and lasts longer, but it may not work in all circuits
due to the lower plate current rating.

The 5W4 has a Vdrop of 45, Compared to a 5Y3 with a Vdrop of 60

http://www.fourwater.com/files/fullrect.txt

Thanks! So if I'm understanding this properly using the 5y3 would result in less power getting to the tubes right?

[OldTube Guy]

Originally Posted by Isaacc7

Thanks! So if I'm understanding this properly using the 5y3 would result in less power getting to the tubes right?

Look at the table in the prior post. The 5W4 and 5Y3G have different voltage drops, but the max plate voltage is 350 for both tubes.

[Isaacc7]

Current combo:


Those Cossor tubes are dead ringers for the GEC VT60, an 807 they made for the military. The input tube is the CV1102 from MOV. Really rich, deep sound. Bass is a little wooly but I'll forgive it because of how good everything else sounds.

[OldTube Guy]

Originally Posted by khashmi

On the subject of rectifiers, I was reading earlier in the thread that it didn’t make much difference for folks with the IIPS mod? Is that something standard now since it was introduced? Trying to understand where I should spend my time and money in terms of rolling. For example yesterday I spent sometime reading up on the famed Mullard GZ34 rectifier. My takeaway was that it is almost universally beloved and lasts a lifetime. So, my question is if rectifiers don’t really make a big difference, should I focus my rolling dollars on output and input tubes and just leave the GE 5U4G be or is there something to getting a rectifier of each type, 5A4/GZ34, 5Y3, Sophia 274b mesh plate depending on the output tubes I may be using?

The KT88 SE is fully tube rectified. Changing rectifiers will change the sound.
When running 6V6G or 6L6G or GA tubes, use a 5Y3.

[khashmi]

Originally Posted by OldTube Guy

The KT88 SE is fully tube rectified. Changing rectifiers will change the sound.
When running 6V6G or 6L6G or GA tubes, use a 5Y3.

Thanks! I do have the Pope 6V6GT’s which I believe can be safely driven with a 5U4G, but I will look in to getting a 5Y3 rectifier to compare. Any particular brand to look out for?

On the other end of the power spectrum I plan to gun for the 5AR4/GZ34. Those vintage Mullards are expensive…