So I have had this board for almost a year and figured I should get busy on ordering some part so I can get started and finished on this. I am trying to model mine after one that George "aka Mr. Tubelab " mentioned in a post here.
"I have another SSE that uses the larger CXSE-25-8-5K transformers playing through a home built set of speakers that use 15 inch woofers with 96db efficiency. There is NO subwoofers, but the bass from this SSE can be felt INSIDE the HOUSE ACROSS THE STREET! This SSE can produce 15 watts from 20 Hz to 18 KHz. NO SUB NEEDED, or wanted. In this case the Electro Harmonix KT88 or 6550 tube produces the best most well controlled bass and power. I use UL mode with the CFB turned on. Pink Floyd, Depeche Mode, Metallica, all sound great at high volumes".
I have attached a sheet with part #s mostly from Digikey and would like some input to make sure I am ordering the correct parts.
Also there are a few things I can find or are not sure what to get:
Rectifier Switch, Mode Switch, Feedback Switch, Auxiliary power supply cap, C3 the 0.47 100V Mylar cap, And a couple of other questions that are on the attached sheet. THANK YOU VERY MUCH AND HAPPY NEW YEAR!
Also be gentle with me this is my 1st tube amp build and I am open for suggestions.
"I have another SSE that uses the larger CXSE-25-8-5K transformers playing through a home built set of speakers that use 15 inch woofers with 96db efficiency. There is NO subwoofers, but the bass from this SSE can be felt INSIDE the HOUSE ACROSS THE STREET! This SSE can produce 15 watts from 20 Hz to 18 KHz. NO SUB NEEDED, or wanted. In this case the Electro Harmonix KT88 or 6550 tube produces the best most well controlled bass and power. I use UL mode with the CFB turned on. Pink Floyd, Depeche Mode, Metallica, all sound great at high volumes".
I have attached a sheet with part #s mostly from Digikey and would like some input to make sure I am ordering the correct parts.
Also there are a few things I can find or are not sure what to get:
Rectifier Switch, Mode Switch, Feedback Switch, Auxiliary power supply cap, C3 the 0.47 100V Mylar cap, And a couple of other questions that are on the attached sheet. THANK YOU VERY MUCH AND HAPPY NEW YEAR!
Also be gentle with me this is my 1st tube amp build and I am open for suggestions.
Hi MuffinMan
I'm a complete noob but I completed my 3rd SSE just before the holidays (gift for my son) so if I can do it... In all three I just followed directions, checked my work carefully, followed common sense safety precautions, plugged the thing in and it worked. My first one is here in my studio and is on 10 hours a day, usually 6 days a week and is now almost 2 years old.
I didn't see anyone else chime in and I'm by no means an expert but here goes:
I didn't check all the exact part numbers for the capacitors and resistors against what I used/ordered but they look okay. Do check your resistors carefully and use a color code calculator before soldering in - my last order from DigiKey they gave me the wrong values on a few.
GZ-34 and 5AR4 - different numbers for same tube. I used a Sovtek, seems fine.
My rectifier switch is a simple SPST. The Mode and Feedback were DPDT from what I recall - these I had lying around. I didn't include the second 2 options in my last 2 builds - didn't feel they were necessary and just kept the amp basic.
Missing from your list are the inrush current limiter and diodes, both part of the tube rectification. It's a CL 140 (KC014L-ND) and two diodes (UF4007TR-ND). I know you didn't specifify it but for SS rectification it was recommended that a CL 90 be placed inline with the power transformer primary. I put that in mine regardless, it provides a bit of a "soft start."
I didn't see a potentiometer - you'll need one if you intent to have volume control.
In my first 2 builds I used a Hammond 194D (5H 160ma) and in the last the Edcor CXC125 (10H 200 ma). I can't tell the difference sonically. To be honest, I choose the Hammond because it was smaller and I could mount it inside. The bigger Edcor is on the "showy" amp. From George "Just about any choke that can handle 150 mA or more will work. Aim for 5 to 10 Hy and a DC resistance between 100 and 250 ohms."
Also from George on the Aux Cap "The aux cap should be a motor run (NOT motor start) cap. Motor run caps are made for a very low ESR and work synergistically with the electrolytic to form a very good low cost solution. These are usually rated in AC volts and should be 370 VAC or higher. Any capacitance value from 40 uF to 100 uF will work. I usually shop for 80 or 100 uF motor runs on Ebay and have found them for $15 to $20."
I used Edcor for my power transformers to save on shipping - just got all the heavy iron from the same place. I know they say 8 weeks but stuff generally showed up in around 4 to 5 weeks. Waiting for the iron gives you plenty of time to populate the board and get your case ready.
Let me know if you have any more questions.
After building 3 of these sort of like "paint by numbers" I really want to know a little more about how these work and have bought a few books to help on that front. After getting through those I want to build a lower output SSE to utilize some NOS tubes I got at a flea market and then next, a TSE. There's a ton of info on this Tubelab forum but it's a lot to wade through but in most cases, if I had a question - it was there somewhere.
Best of luck on this, I really enjoy these amps - both building them (the cases less so I must admit) and listening to them. My son fired up his new SSE on Christmas and was listening to music he was familiar with and commented on hearing things he never heard before. To go with his SSE I found a pair of NIB KLH speakers dated 1970 on eBay - made for a great combo.
I'm a complete noob but I completed my 3rd SSE just before the holidays (gift for my son) so if I can do it... In all three I just followed directions, checked my work carefully, followed common sense safety precautions, plugged the thing in and it worked. My first one is here in my studio and is on 10 hours a day, usually 6 days a week and is now almost 2 years old.
I didn't see anyone else chime in and I'm by no means an expert but here goes:
I didn't check all the exact part numbers for the capacitors and resistors against what I used/ordered but they look okay. Do check your resistors carefully and use a color code calculator before soldering in - my last order from DigiKey they gave me the wrong values on a few.
GZ-34 and 5AR4 - different numbers for same tube. I used a Sovtek, seems fine.
My rectifier switch is a simple SPST. The Mode and Feedback were DPDT from what I recall - these I had lying around. I didn't include the second 2 options in my last 2 builds - didn't feel they were necessary and just kept the amp basic.
Missing from your list are the inrush current limiter and diodes, both part of the tube rectification. It's a CL 140 (KC014L-ND) and two diodes (UF4007TR-ND). I know you didn't specifify it but for SS rectification it was recommended that a CL 90 be placed inline with the power transformer primary. I put that in mine regardless, it provides a bit of a "soft start."
I didn't see a potentiometer - you'll need one if you intent to have volume control.
In my first 2 builds I used a Hammond 194D (5H 160ma) and in the last the Edcor CXC125 (10H 200 ma). I can't tell the difference sonically. To be honest, I choose the Hammond because it was smaller and I could mount it inside. The bigger Edcor is on the "showy" amp. From George "Just about any choke that can handle 150 mA or more will work. Aim for 5 to 10 Hy and a DC resistance between 100 and 250 ohms."
Also from George on the Aux Cap "The aux cap should be a motor run (NOT motor start) cap. Motor run caps are made for a very low ESR and work synergistically with the electrolytic to form a very good low cost solution. These are usually rated in AC volts and should be 370 VAC or higher. Any capacitance value from 40 uF to 100 uF will work. I usually shop for 80 or 100 uF motor runs on Ebay and have found them for $15 to $20."
I used Edcor for my power transformers to save on shipping - just got all the heavy iron from the same place. I know they say 8 weeks but stuff generally showed up in around 4 to 5 weeks. Waiting for the iron gives you plenty of time to populate the board and get your case ready.
Let me know if you have any more questions.
After building 3 of these sort of like "paint by numbers" I really want to know a little more about how these work and have bought a few books to help on that front. After getting through those I want to build a lower output SSE to utilize some NOS tubes I got at a flea market and then next, a TSE. There's a ton of info on this Tubelab forum but it's a lot to wade through but in most cases, if I had a question - it was there somewhere.
Best of luck on this, I really enjoy these amps - both building them (the cases less so I must admit) and listening to them. My son fired up his new SSE on Christmas and was listening to music he was familiar with and commented on hearing things he never heard before. To go with his SSE I found a pair of NIB KLH speakers dated 1970 on eBay - made for a great combo.
I kept my first SSE very simple and eliminated most of the switches. I've also had good luck with the Sovtek 5AR4. If you are going to hide your choke a Triad C-14X is inexpensive and works great.
I used Temco 100mfd Run Capacitor available on ebay for $13.50.
I found a 21 step attenuator that others had recommended on ebay as well.
Good luck with your project.
I used Temco 100mfd Run Capacitor available on ebay for $13.50.
I found a 21 step attenuator that others had recommended on ebay as well.
Good luck with your project.
47uF is an acceptable value for C1, but no higher. (I think it's in the build notes from George) I have been running my SSE with a 47uF input capacitor for at least eight years now with no problems.
The input thermistors will also reduce the inrush current, which could *potentially* allow for a larger input cap, but I always like to stick to the datasheet recommendations.
If you play with PSU Designer from Duncan Amps, you will see that a small variation in the input cap has less impact than the second cap in the crc/clc filter.
It's nice to see that Digikey now has multiple 500V rated parts.
Good luck with the build, you will be rewarded.
-Phil
How does this look spec wise for a power switch? https://www.digikey.com/product-detail/en/delta-electronics/06AK2D/603-1131-ND/1718576
Attachments
I've used this one a few times. I like having the flange to connect it to the chassis. It seems very similar to the one you have selected
764-00/003 Qualtek | Connectors, Interconnects | DigiKey
764-00/003 Qualtek | Connectors, Interconnects | DigiKey
After I get the amp running I want to add some meters to it. How hard would it be to wire in some of the VU meters as seen on this Mcintosh MC2102 .
And 1 more question, I want to make a face-plate something like the one on the Mcintosh MC2102
that will allow a color to come through (green on the Mac) instead of having the face-plate engraved. Any suggestions?
And 1 more question, I want to make a face-plate something like the one on the Mcintosh MC2102
that will allow a color to come through (green on the Mac) instead of having the face-plate engraved. Any suggestions?
Attachments
I am ready to order the Big Iron. I am getting the Edcor CXSE25-5K. If I remember correctly I have to specify Secondary (Output) Impedance * of 8 Ω is this correct? Here is the link Thanks
EDCOR - CXSE25-5K
EDCOR - CXSE25-5K
Yes, thanks Hannibal 8,,
Is this the correct part for R14 & R24 ? 3 Watt Metal Oxide Power Resistor
| TubeDepot.com and then I select 10k in the dropdown? And then do
I select 150K for R2 ?
Is this the correct part for R14 & R24 ? 3 Watt Metal Oxide Power Resistor
| TubeDepot.com and then I select 10k in the dropdown? And then do
I select 150K for R2 ?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.