RH84 Finished- Voltage question

[roren]

The first cap should ony be 20UF , with a 5Y3GT , or use two of them with a 40 UF cap

Yes of course, Thanks Mark.
Alex also mentioned that he wanted to try CLCL. I guesse I have to start my PSUD2
and try some combinations.
Alex, do you remember what values you used? can you give me a hint? Is there
any PSU ripple cancelation in this RH amp? Many questions

Rolf

[DeathRex]

Magnus, or DIYtube nic soundbrigade is in Sweden.

[roren]

Magnus, or DIYtube nic soundbrigade is in Sweden.

Yes Thanks, I know him from a local web forum here in Sweden. So you mean
that I should ask him. Okey I might just do that.

Thanks again

Rolf

[Shannon Parks]

Rolf, checkout my get*set*go schematic (on one of the sub forums). You can get fantastic ripple rejection with a simple CLCRC or CLCLC with only 1H or 1.5H inductors. They're cheap and small (fit under the chassis). I've continued to use this method with my Clementine and Budgie SE and new 300B amp. You can use it with any Class A amp.

Shannon

[roren]

Thank you separks, I'll check it out

[Alex Kitic]

Hi,
I'm glad to see that this RH design is still up.
I like the simplicity of it. I plan to build me one to have for my nearly finished
High efficiency speakers.
I happend to have a lot of '5Y3GT' rectifier tubes, And I just wonder if there
is something I have to change in the published schematic when using 5Y3GT.

Rolf

Hi, RH is very much alive :)

If you are interested in building an RH84 and using a 5Y3GT, I would recommend you to adopt the CLCL configuration. This means choke input filter, with a further choke+cap combination following the first.

I would like to stress that you do not need to use 2x 5Y3 for the RH84, one is enough provided you adopt the choke input filter configuration. You can check for yourself in datasheets, it is safe untill 135mA DC which is more than needed for an RH84.

Of course, you would need to adjust the HT secondary since the voltage drop across 5Y3GT would be more than across the 5U4.

[Alex Kitic]

Rolf, checkout my get*set*go schematic (on one of the sub forums). You can get fantastic ripple rejection with a simple CLCRC or CLCLC with only 1H or 1.5H inductors. They're cheap and small (fit under the chassis). I've continued to use this method with my Clementine and Budgie SE and new 300B amp. You can use it with any Class A amp.

Shannon

While on one hand you do not need to use 5H or 10H chokes, the story is not about ripple rejection. The ripple rejection can be achieved with normal C-R-C filters, and especially with regulation...

Chokes that are too small will not regulate in the choke input position, and on the other hand choke input sounds and performs way better than cap input filters -- regardless of the fact that we are speaking of SE amps were the current draw of the output stage (audio stage) is constant, unlike the current draw of class AB push-pull amps.

[Alex Kitic]

Alex, do you remember what values you used? can you give me a hint? Is there
any PSU ripple cancelation in this RH amp? Many questions

Rolf

For ideas on what I mean by LCLC check out the RH Universal thread. While you do not need 200mA chokes (100mA would suffice) or 500uF caps (although it is up to you), that is basically the configuration you should consider.

Keep in mind that a 100mA choke will have higher DCR than a 200mA choke due to the thickness of wire used (and particularly if it is a 10H choke, not a 5H choke, due to the number of turns...).

[roren]

My memory is not to be trusted,sorry. After checking my tube stock I noticed
that I have no 5Y3GT's. On the other hand I have a lot of NOS 5Y4GT. Maybe
they can be used just as well?

[Alex Kitic]

My memory is not to be trusted,sorry. After checking my tube stock I noticed
that I have no 5Y3GT's. On the other hand I have a lot of NOS 5Y4GT. Maybe
they can be used just as well?

Yes they can -- the 5Y4GT is electrically identical to the 5Y3GT but has a different pinout. Once you wire the socket for 5Y4, you will not be able to use it with other standard rectifier tubes.

[roren]

Yes they can -- the 5Y4GT is electrically identical to the 5Y3GT but has a different pinout. Once you wire the socket for 5Y4, you will not be able to use it with other standard rectifier tubes.

Thats good. I did some research after my previous post. And find what you just said.
Next time I check 'TDSL2' before I flood this forum with my questions

[EWBrown]

You can make the rectifier tube's socket to be able to accept either the 5Y3GT or 5Y4GT

This should work:

connect pin 3 to pin 4

connect pin 5 to pin 6

connect pin 2 to pin 7

Take rectified DC voltage output from pin 8.

HTH

/ed B inNC

[Alex Kitic]

You can make the rectifier tube's socket to be able to accept either the 5Y3GT or 5Y4GT

This should work:

connect pin 3 to pin 4

connect pin 5 to pin 6

connect pin 2 to pin 7

Take rectified DC voltage output from pin 8.

HTH

/ed B inNC

[nyazzip]

my rh-84 has been up for 8-10 months now, i believe. i just tested the plate voltage and got 333v on the el84....thats about where most of my el-84 guitar amps run so i'm not too alarmed.
this was a point to point build so probing around is a bit like playing the '60s game "Operation"....except the consequences are much higher!
which led me to think of something, i wonder if that game was sorta meant to prep Cold War children to solder on high voltage circuits....?

[Alex Kitic]

my rh-84 has been up for 8-10 months now, i believe. i just tested the plate voltage and got 333v on the el84....thats about where most of my el-84 guitar amps run so i'm not too alarmed.

It's not clear from the description whether you are measuring the voltage on the second cap (i.e. "above" the OPT), or at the anode ("below" the OPT)?

If we assume that you are measuring the B+ entering the OPT, this means that from 333V you should deduct the approx. 12V loss through the Rk and some 15V loss through the primary of the OPT, which is usually about 300 ohm DCR). That would mean 306V across the tube, i.e. anode to cathode, which is OK (actually, allows the highest output power from the RH84).