When using dual tube rectifiers, say two GZ34s, what would the maximum value for the reservoir cap be?
Datasheets say 60u for a single. Is there a rule of thumb for two. Still 60u? 120u?
Mesa Dual Recs run two 220u in series for 110u.
Dual Rectifier Reservoir Cap ?
Moderators: pompeiisneaks, Colossal
-
dorrisant
- Posts: 2790
- Joined: Tue Sep 21, 2010 1:27 pm
- Location: Somewhere between a river and a cornfield
- Contact:
Dual Rectifier Reservoir Cap ?
"Education is what you're left with after you have forgotten what you have learned" - Enzo
-
martin manning
- Posts: 14308
- Joined: Sun Jul 06, 2008 12:43 am
- Location: 39°06' N 84°30' W
Re: Dual Rectifier Reservoir Cap ?
Doubling the allowable capacitance sounds right. Notice Boogie paralleled one diode from each tube on each side of the HT, matching the pin numbers, and I would do the same.
-
Stevem
- Posts: 5144
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: Dual Rectifier Reservoir Cap ?
These Masa duel recto amps have the dam smallest PT and OT that I have ever seen in a so called 100 watt amp!
That's no dought why they only output like 82 watts RMS at best!
If it where may amp I would parallel two stacks of 220 uf caps to beef up that first power node!
That's no dought why they only output like 82 watts RMS at best!
If it where may amp I would parallel two stacks of 220 uf caps to beef up that first power node!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Dual Rectifier Reservoir Cap ?
You cannot have 220 microFarads after two paralleled GZ34s, just half of it.
That's what the Recto Dual has. To have 220 you need four GZ34s, but then what would be the point of the stiffness of the power supply with the sag of the tube rectification? It could be useful to have 110 microF (or even less) when tube rectified and 220 when diode rectified.
That's what the Recto Dual has. To have 220 you need four GZ34s, but then what would be the point of the stiffness of the power supply with the sag of the tube rectification? It could be useful to have 110 microF (or even less) when tube rectified and 220 when diode rectified.
-
dorrisant
- Posts: 2790
- Joined: Tue Sep 21, 2010 1:27 pm
- Location: Somewhere between a river and a cornfield
- Contact:
Re: Dual Rectifier Reservoir Cap ?
Yes, I was thinking 120µF max.roberto wrote: ↑Wed May 01, 2019 9:24 pm You cannot have 220 microFarads after two paralleled GZ34s, just half of it.
That's what the Recto Dual has. To have 220 you need four GZ34s, but then what would be the point of the stiffness of the power supply with the sag of the tube rectification? It could be useful to have 110 microF (or even less) when tube rectified and 220 when diode rectified.
"Education is what you're left with after you have forgotten what you have learned" - Enzo
-
Stevem
- Posts: 5144
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: Dual Rectifier Reservoir Cap ?
With a thermistor or two in the AC line you could to soft start the amp!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
-
dorrisant
- Posts: 2790
- Joined: Tue Sep 21, 2010 1:27 pm
- Location: Somewhere between a river and a cornfield
- Contact:
Re: Dual Rectifier Reservoir Cap ?
I started the topic, so it's ok if I derail a bit, right?
Please explain Steve. I'm all ears!
"Education is what you're left with after you have forgotten what you have learned" - Enzo
-
pompeiisneaks
- Site Admin
- Posts: 4244
- Joined: Sat Jan 14, 2017 4:36 pm
- Location: Washington State, USA
- Contact:
Re: Dual Rectifier Reservoir Cap ?
The thermistor's reduce inrush current until the amp gets going, so you can avoid the rectifier getting hit too hard when it first powers up. A nice, slow startup.
~Phil
tUber Nerd!