But... IF you can live with the +6dB gain (I can't use it... Way to much gain/microphonics), and IF you don't hear the sound degrading from not loading the output with the resistor network, then you can do like SJS; remove the resistor network, use 1M ohm to ground, use a small output cap and still have a low corner freq, provided that the input impedance is relatively high on the amp.
With a 1 uF output cap and 100k ohm input impedance on the amp the corner freq will be 1.8hz... If the input impedance on the amp is -for instance- 22K ohm the corner freq will be 7,2hz (that's too high meaning a larger cap would be needed)
With a 1 uF output cap and 100k ohm input impedance on the amp the corner freq will be 1.8hz... If the input impedance on the amp is -for instance- 22K ohm the corner freq will be 7,2hz (that's too high meaning a larger cap would be needed)
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Morten, I will lay down on my sword and say that the Philips 5R4GYS is a fantastic sounding tube. It even kills the GEC U52 tube. The Philips tube has an extremely full sweet life like sound as though you are listening to the musicians in front of you. The sound stage fills the whole room. I am using Brimar (USA made) 45 tubes and National Electron 6AS7. A very nice toe tapping sound indeed.
Peter
Peter
GZ33 rectifier
Has anyone got a GZ33 they can try?
I got a GZ33 off eBay and just listened versus the Philips 5R4GYS thanks to Peter who very kindly cannibalised his own Tram2 to fix mine.
The ridiculously early impression before either rectifier has been run in is that the Mullard is better. The dynamics are more powerful, the imaging layering more precise and cymbals less tizzy. Of course that could all change in a few weeks.
The GZ33 has some robust specs, has a reputation for long life but apparently drops voltage more over the plates. Does that matter?
Has anyone got a GZ33 they can try?
I got a GZ33 off eBay and just listened versus the Philips 5R4GYS thanks to Peter who very kindly cannibalised his own Tram2 to fix mine.
The ridiculously early impression before either rectifier has been run in is that the Mullard is better. The dynamics are more powerful, the imaging layering more precise and cymbals less tizzy. Of course that could all change in a few weeks.
The GZ33 has some robust specs, has a reputation for long life but apparently drops voltage more over the plates. Does that matter?
I'm looking into Mu tubes... The Chatham Electronics 6AS7G are very nice sounding, and should be some of the best 6AS7G types. Then I read that 5998 can be replaced for 6AS7G, and to make it even more complicated, then 5998 is sometimes labeled 2399 - like the Chatham Electronic I just bought. The 5998 / 2399 has totally different internal construction than 6AS7G, so I was a bit skeptical when installing in my Tram II yesterday, but there is music 
Time to burn in the tube, it will be interesting if it works even better than the Chatham Electronics 6AS7G
PS...Interesting with the GZ33 rectifiers, let us know what you think of the sound as they (and the Philips) burn in. In my experience the Philips changes quite a lot, maybe the same goes for the GZ33...Tizzy cymbals is not something I hear with the Philips, actually quite the opposite. What I like so much with the Philips is it's very natural and coherent sound where nothing ''stands out''...
Time to burn in the tube, it will be interesting if it works even better than the Chatham Electronics 6AS7GPS...Interesting with the GZ33 rectifiers, let us know what you think of the sound as they (and the Philips) burn in. In my experience the Philips changes quite a lot, maybe the same goes for the GZ33...Tizzy cymbals is not something I hear with the Philips, actually quite the opposite. What I like so much with the Philips is it's very natural and coherent sound where nothing ''stands out''...
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The 5998 has a different mu rating to the 6AS7G.
6AS7G Mu = 2 Gm = 7000, Rplate = 280 ohms
5998 Mu = 5.4 Gm = 15500, Rplate = 350 ohms,
6080 Mu = 2, Gm = 6500-7000, Rplate = 280-300 ohms
6520 Mu = 2 (1.9-2.4) Gm 6400 - 7600
6H13C Mu=2.4 ?????
7236 Mu = 4.8 Gm = 12500, Rplate = 350 ohms
Does that matter in its use as a mu tube?
I was too ignorant of the circuit to try it so I'm fascinated to follow your findings. Thanks again.
PS I using the Philips 5R4GYS at the moment and its sublime.
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Aha! Can you please post the Marantz model number(s)? A couple of months ago i made a post in another thread about getting a Logitech Harmony Remote to work on the Tram2 by selecting a Marantz amplifier. Volume works a treat, but I don't yet have the input switching working. If you can post the model number of the Marantz amplifier, then anyone should be able to use that to get their Logitech Harmony Remote to work (assuming that the amplifier model is in the Logitech database).
Hi Morten
I am reading this thread quite a while. Congratulations on your mods , every single time executed neat and skillful. Great ideas here and fantastic atmosphere of sharing knowledge about this design. Regarding your 2399 ,it actually looks more like 5998 any brand inside than 6AS7G itself. Never tried those you have got ,by the way ,but they look pretty intriguing.
Regarding rectifiers shout out I would agree with your opinion about Mullard vs. Phillips having both long time and using in different amplifiers . It is more the matter of taste and getting balance in sound with particular electronics one is using than the class , where both are at its own. Going for GZ 37 for example will push tonal balance even more further into bass direction and give more meaty presentation , but sacrifice some dynamics , so it is always courses for horses and the matter of taste. I would like to recommend one more and not so expensive to buy for trying :
Chatham JAN-CAHG 5R4WGA rectifier. [ mine are all dated 5/ 1956 ]
I found them to be very interesting alternative if compared against those mentioned above , and they always seemed to be most powerful of all if it comes to micro dynamics and speed. But again , I have never tried them in TRAM design , as I do not own it, BUT ... things might change soon as I had been offered to buy one and I am very looking forward to give it a run in my own rig. It belongs there as my amplification is dominated by 45 and 2A3 valves - among my favorites, hence an interest in this long time and excellent thread . All the best to all others who contributed into quality of this writing here , with greatest respect , Txs Gents
I am reading this thread quite a while. Congratulations on your mods , every single time executed neat and skillful. Great ideas here and fantastic atmosphere of sharing knowledge about this design. Regarding your 2399 ,it actually looks more like 5998 any brand inside than 6AS7G itself. Never tried those you have got ,by the way ,but they look pretty intriguing.
Regarding rectifiers shout out I would agree with your opinion about Mullard vs. Phillips having both long time and using in different amplifiers . It is more the matter of taste and getting balance in sound with particular electronics one is using than the class , where both are at its own. Going for GZ 37 for example will push tonal balance even more further into bass direction and give more meaty presentation , but sacrifice some dynamics , so it is always courses for horses and the matter of taste. I would like to recommend one more and not so expensive to buy for trying :
Chatham JAN-CAHG 5R4WGA rectifier. [ mine are all dated 5/ 1956 ]
I found them to be very interesting alternative if compared against those mentioned above , and they always seemed to be most powerful of all if it comes to micro dynamics and speed. But again , I have never tried them in TRAM design , as I do not own it, BUT ... things might change soon as I had been offered to buy one and I am very looking forward to give it a run in my own rig. It belongs there as my amplification is dominated by 45 and 2A3 valves - among my favorites, hence an interest in this long time and excellent thread . All the best to all others who contributed into quality of this writing here , with greatest respect , Txs Gents
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The B
I have a 5R4WGB here from another amp so Ill give it a spin in my Tram2 and report back soon. I dont know how its meant to sound compared to the recommended 5R4WGA? The B model is ruggedized and made with stringent quality control so its good for 60,000' - just what the high flying Tram2 owner needs
I hope you enjoy your Tram2 audition. Just be careful running 2A3's unless you know it has heater regulators installed that can handle the load
...... I would like to recommend one more .
Chatham JAN-CAHG 5R4WGA rectifier.
I have a 5R4WGB here from another amp so Ill give it a spin in my Tram2 and report back soon. I dont know how its meant to sound compared to the recommended 5R4WGA? The B model is ruggedized and made with stringent quality control so its good for 60,000' - just what the high flying Tram2 owner needs
I hope you enjoy your Tram2 audition. Just be careful running 2A3's unless you know it has heater regulators installed that can handle the load
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I have the Marantz remote RC5200SR. It works selecting the TUNER function. For coding select any Marantz AV Receiver eg SR-7200 or SR-4200 should work and are in the Logitech database. Enjoy.
Just tried my 5R4WGB rectifier vs a GZ33. Both are well used. The Tram2 still has Version II regulators and was running NU45's with an RCA6AS7.
Im my system the 5R4WGB was mildly noisy with hum. The hum might be partly due to a radiated field effect. Waving my hand near the rectifier made the hum more intense even with 45's shielded with tin can's.
The GZ33 in contrast had no hum even with the magic hand trick. The GZ33 to me sounded better with the music tighter and bass cleaner.
Id be interested to read how the recommended Chatham JAN-CAHG 5R4WGA sound if someone has one to try.
My Philips rectifier is sounding much better now it has over ten hours on it.
Im my system the 5R4WGB was mildly noisy with hum. The hum might be partly due to a radiated field effect. Waving my hand near the rectifier made the hum more intense even with 45's shielded with tin can's.
The GZ33 in contrast had no hum even with the magic hand trick. The GZ33 to me sounded better with the music tighter and bass cleaner.
Id be interested to read how the recommended Chatham JAN-CAHG 5R4WGA sound if someone has one to try.
My Philips rectifier is sounding much better now it has over ten hours on it.
Hi Morten
I am reading this thread quite a while. Congratulations on your mods , every single time executed neat and skillful. Great ideas here and fantastic atmosphere of sharing knowledge about this design. Regarding your 2399 ,it actually looks more like 5998 any brand inside than 6AS7G itself. Never tried those you have got ,by the way ,but they look pretty intriguing.
Regarding rectifiers shout out I would agree with your opinion about Mullard vs. Phillips having both long time and using in different amplifiers . It is more the matter of taste and getting balance in sound with particular electronics one is using than the class , where both are at its own. Going for GZ 37 for example will push tonal balance even more further into bass direction and give more meaty presentation , but sacrifice some dynamics , so it is always courses for horses and the matter of taste. I would like to recommend one more and not so expensive to buy for trying :
Chatham JAN-CAHG 5R4WGA rectifier. [ mine are all dated 5/ 1956 ]
I found them to be very interesting alternative if compared against those mentioned above , and they always seemed to be most powerful of all if it comes to micro dynamics and speed. But again , I have never tried them in TRAM design , as I do not own it, BUT ... things might change soon as I had been offered to buy one and I am very looking forward to give it a run in my own rig. It belongs there as my amplification is dominated by 45 and 2A3 valves - among my favorites, hence an interest in this long time and excellent thread . All the best to all others who contributed into quality of this writing here , with greatest respect , Txs Gents
Thanks for the heads up on the 5R4WGA rectifiers, I have never heard about these tubes before (does this ever end..?)
Maybe I did not write clear enough regarding the 2399 tube... The 2399 is a 5998 that is for some reason branded 2399. It's NOT a 6AS7G tube..! So it's not that strange that it looks like a 5998 in it's structure
Fit some nice 2A3's from your collection when you get the Tram II, and let us know how you like the sound..!?
Thanks for the heads up on the 5R4WGA rectifiers, I have never heard about these tubes before (does this ever end..?)
Maybe I did not write clear enough regarding the 2399 tube... The 2399 is a 5998 that is for some reason branded 2399. It's NOT a 6AS7G tube..! So it's not that strange that it looks like a 5998 in it's structure
Fit some nice 2A3's from your collection when you get the Tram II, and let us know how you like the sound..!?
* That's the best of it ,isn't it , so far if it doesn't brake the bank and allows applying little changes to overall voicing of the unit - it's just great
...by the way if you want to try it in your pre I can sent it to you , as I have 3 of them all together with myself.
* Right I see that now ; )
* I have following 2A3 :
Sovtek, old RCAs. KR Audio , Black Treasures(on loan) and TJ 2A3/n , special edition fake mesh plates
- will see how they do in my rig.
I also have following 45:
EML45 solid plate , VAIC 45 solid plate ,and some old ones different kind.
I will try them all ,with an accent put on the new ones and will report here about my findings. Further I will be glad to try different Mu Valve too ,but for now it's better to do one thing on time. I am carefully keep watching all your notes about 6AS7 / 5998 / 2399 so far
Thanks for all answers , also PMs
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Wow, a nice collection of 2A3 and 45 tubes..! It would be really cool, if you could write a bit about their sonic footprint when used in the Tram II..!? The only ones from your collection that I know well is the Treasure 2A3-Z... Here in my system they are more full in the bass and less resolved than the TJ 2A3/SE that are much more open and linear sounding (in my system)...
I notice a few mesh-plates amongst your collection... The general rule is, that anything mesh-plate is too microphonic for the Tram, but it will be interesting to hear your feedback on this.
I notice a few mesh-plates amongst your collection... The general rule is, that anything mesh-plate is too microphonic for the Tram, but it will be interesting to hear your feedback on this.
Will this 2.5V 300B work in the Tram2 with the standard and the Coleman regulators?
300B-Specs vs 2A3-Specs
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It will act same as 2A3 in a circuit . I used those in my Fi X amp back in time, having loaners on the hand. For me replacing 2A3 for 300b , as this is what it does in a case of voicing, doesn't have any sense - simply because 2A3 posses superior sound signature if compared to 300b. My usual departure is other direction If one day they ever build 300b spec'ed 45 ,that would be way to go for to me
As old wise Japanese use to say :
The best 300b is ... 2A3 ,and the best 2A3 is 45 !
This formula have always worked for me fine, but it is just me, others might prefer sth different.
Anyway I keep thinking if presumably going down this route will make the best 45 ... WE 101D ?
As such an amp is now commercially available I have quite a dilemma ,hahaha
If one day they ever build 300b spec'ed 45 ,that would be way to go for to me As old wise Japanese use to say :
The best 300b is ... 2A3
,and the best 2A3 is 45 !This formula have always worked for me fine, but it is just me, others might prefer sth different.
Anyway I keep thinking if presumably going down this route will make the best 45 ... WE 101D ?
As such an amp is now commercially available I have quite a dilemma ,hahaha
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