Hi everyone
A couple of years ago I designed a 5W+5W stereo amp using 12AT7's and EL34's, and a solid state inverter power supply. The concept was to make a top quality SE tube amp which would be easy to build with little point-to-point wiring, and with a good looking pre-drilled chassis.
Over the past few years quite a few have been built and to my knowledge they are all performing as expected, so I've put the entire design up on the internet to see what happens. Sort of an experiment.
Basically I'm a retired electronics and telecommunications guy just doing it as a hobby business to have a bit of fun in between sailing and motorbikes. I'm selling pcb's, a chassis kit, and output transformers to whoever wants to make one, (you dont need to buy anything from me, but it would make life a lot easier).
The full information is at Tube - Valve Stereo Amplifier to Build Yourself | RedRoo Kits
I hope you enjoy reading. I'm now working on a guitar amp 🙂
Tube - Valve Stereo Amplifier to Build Yourself | RedRoo Kits
A couple of years ago I designed a 5W+5W stereo amp using 12AT7's and EL34's, and a solid state inverter power supply. The concept was to make a top quality SE tube amp which would be easy to build with little point-to-point wiring, and with a good looking pre-drilled chassis.
Over the past few years quite a few have been built and to my knowledge they are all performing as expected, so I've put the entire design up on the internet to see what happens. Sort of an experiment.
Basically I'm a retired electronics and telecommunications guy just doing it as a hobby business to have a bit of fun in between sailing and motorbikes. I'm selling pcb's, a chassis kit, and output transformers to whoever wants to make one, (you dont need to buy anything from me, but it would make life a lot easier).
The full information is at Tube - Valve Stereo Amplifier to Build Yourself | RedRoo Kits
I hope you enjoy reading. I'm now working on a guitar amp 🙂
Tube - Valve Stereo Amplifier to Build Yourself | RedRoo Kits
Just an update for those who are interested ....... I've updated the RedRoo DIY information to specify the 12AT7EH tube from Electro-harmonix. The reason for this is that the EH version has a heater-cathode voltage specification of 200V which is better for the cathode follower stage. Other manufacturers mostly specify 90V h/k.
Not sure if there is any real difference between the manufacturers, or if its just the way they specify it. I have seen various thoughts about this, but best to be sure.
(Increasing R11 to reduce the B+ voltage on V1 to about 200V would achieve the same thing)
Interested in your thoughts about this..
Not sure if there is any real difference between the manufacturers, or if its just the way they specify it. I have seen various thoughts about this, but best to be sure.
(Increasing R11 to reduce the B+ voltage on V1 to about 200V would achieve the same thing)
Interested in your thoughts about this..
I'm curious why the bottom two front panel screws are missing in the picture on the front page of your website.
Neat kit, though. Can the LEDs under the tubes be a different colour? Like a pretty HeNe red?
Tom
Neat kit, though. Can the LEDs under the tubes be a different colour? Like a pretty HeNe red?
Tom
Hi. Thanks for spotting that. On the website builder it looks OK because I intentionally cut the bottom off that pic to hide the missing screws (I ran out of red screws), but now when I look at it using the URL the pic has been resized. I guess that's the website's the dynamic layout at work to adjust for different screen sizes? A new batch of screws are arriving this week, so I'll take a new pic and change it.
As far as the LED's go, anything will do but you may need to change the series resistors to adjust the brightness. The hole in the PC Board is 5.5mm dia....Phil
As far as the LED's go, anything will do but you may need to change the series resistors to adjust the brightness. The hole in the PC Board is 5.5mm dia....Phil
It looks to be a full featured, elegant design Phil.
Very decent of you to make this available to the membership.
Beautiful pcb, BTW.
Hugh
Very decent of you to make this available to the membership.
Beautiful pcb, BTW.
Hugh
Ah. You can always crop the image in Photoshop/Gimp/etc., but reshooting with the red screws sounds like a plan. They look good!
Could be. Welcome to web development. 🙂 Your website looks pretty easy to navigate on a phone, by the way. At least I found the navigation easy and intuitive.
I don't see any policy information for shipping, returns, etc. What type of payment is accepted?
If you plan to take payment through PayPal, I suggest looking at PayPal buttons. They're simple to set up on PayPal and the setup will spit out a code snippet that you include on your website. If you have basic HTML editing skills, it's pretty easy to get going and works well as long as you only have a few products. Alternatively your web host probably offers some form of eCommerce system.
I suggest looking into shipping through one of the many shipping aggregators. Basically they allow you to ship through UPS, FedEx, DHL, etc. for exceptionally good rates. Just search for "shipping for small business" and you'll find them.
I realize this could be in the works already.
I hope you don't mind my feedback and suggestions. Feel free to reach out to me directly if you'd like more input on the business side of DIY audio. I'm excited for you. Kudos for starting a new business.
Ah. Good to hear. I'm much a fan of the pretty HeNe red ones. HLMP-D101 for example.
Tom
Hi Tom. Setting up payments and shipping is the next step so your comments/suggestions are really appreciated.
I've got a couple more designs in the pipeline. One is a guitar amp with separate preamp and power amp boards (the power amp board will be suitable for either Hi-Fi or guitar and can be used SE or PP), and an RIAA preamp to match the RedRoo amp. I'm just finding out how little I knew about RIAA preamps!
I've got a couple more designs in the pipeline. One is a guitar amp with separate preamp and power amp boards (the power amp board will be suitable for either Hi-Fi or guitar and can be used SE or PP), and an RIAA preamp to match the RedRoo amp. I'm just finding out how little I knew about RIAA preamps!
Douglas Self has an insightful chapter on RIAA stages in his Small Signal Audio Design book.
Note that a RIAA stage should have good overload behaviour so clicks and pops don't wreck the sound more than the click itself.
I ran Neurochome for 3-4 years using just PayPal buttons. I had maybe ten products then. That worked well - at least while I lived in the US. Once I moved to Canada and switched to an international PayPal account, I recall there being some issue with it. It was something silly like it wouldn't calculate shipping by weight or something. I suggest looking into the limitations and see if they apply to you before you get too far down that path.
If you have the option to integrate an actual eCommerce system that allows you to take credit cards and PayPal (and other online payments if you wish) I recommend getting that set up. Your web host should be able to help you out.
Tom
Note that a RIAA stage should have good overload behaviour so clicks and pops don't wreck the sound more than the click itself.
I ran Neurochome for 3-4 years using just PayPal buttons. I had maybe ten products then. That worked well - at least while I lived in the US. Once I moved to Canada and switched to an international PayPal account, I recall there being some issue with it. It was something silly like it wouldn't calculate shipping by weight or something. I suggest looking into the limitations and see if they apply to you before you get too far down that path.
If you have the option to integrate an actual eCommerce system that allows you to take credit cards and PayPal (and other online payments if you wish) I recommend getting that set up. Your web host should be able to help you out.
Tom
Thanks Tom. My last business was in medical alarms and I didn't need to worry about such things, hi. This one is much more fun.