Hi all!
I'm a relatively new member to the forums and I'd love to pick your brains. So I thank you in advance for any help. Hell, I'll probably thank you afterwards too.
So I've built a few tube guitar amps. All either kits or parts collections and online schematic/ wiring guides. I love it but honestly I don't really play guitar all that much and I usually just give the amps to a friend on indefinite loan.
I'd love to make an amp that I'd really use and so building an amp for my stereo would be ideal.
So, a couple questions:
1) are there any particular kits that you'd recommend?
2) depending on the above answer would I need a separate preamp for phono?
3) overall I'd like to use phono, iPod and ideally the output from my Sonos system as inputs. Separate preamps?
4) what sort of speakers.
I realize that's asking a lot and I likely left out some sort of info required to answer it all, but I'm just looking to build a tube stereo system with those particular inputs.
Thanks!
I'm a relatively new member to the forums and I'd love to pick your brains. So I thank you in advance for any help. Hell, I'll probably thank you afterwards too.
So I've built a few tube guitar amps. All either kits or parts collections and online schematic/ wiring guides. I love it but honestly I don't really play guitar all that much and I usually just give the amps to a friend on indefinite loan.
I'd love to make an amp that I'd really use and so building an amp for my stereo would be ideal.
So, a couple questions:
1) are there any particular kits that you'd recommend?
2) depending on the above answer would I need a separate preamp for phono?
3) overall I'd like to use phono, iPod and ideally the output from my Sonos system as inputs. Separate preamps?
4) what sort of speakers.
I realize that's asking a lot and I likely left out some sort of info required to answer it all, but I'm just looking to build a tube stereo system with those particular inputs.
Thanks!
tubes4hifi.com, dynakitparts.com is places to study for kits. Depending
on your needs and budget all from 2x17w integrated w/riaa input to 125w monoblocks and
separate preamps.
I'd recommend start small, and sell them if you want more, selling a "wellknown" amp is
much easier then selling a one-of-a-kind and modified one.
on your needs and budget all from 2x17w integrated w/riaa input to 125w monoblocks and
separate preamps.
I'd recommend start small, and sell them if you want more, selling a "wellknown" amp is
much easier then selling a one-of-a-kind and modified one.
The speakers that will be used have an enormous influence on what the power amplifier will look like. What sort of speakers are going to be fed. Keep Paul Joppa's 102 dB. rule firmly in mind. Joppa's Rule states that for "typical" listening space volumes, an amp speaker combo should be capable of 102 dB. SPL peaks at a 1 M. distance.
If speakers already on hand are "Watt Hogs" or have serious dips in the impedance curve, which require derating when mated to tubes, a practical solution is tubed preamplification mated to quality SS power amplification.
If speakers already on hand are "Watt Hogs" or have serious dips in the impedance curve, which require derating when mated to tubes, a practical solution is tubed preamplification mated to quality SS power amplification.
Make sure to get Merlin Blencowe's books as well. I tend to like his style of writing a lot. One source many ignore is old EE texts from the 30's and earlier. Many of these have the actual differential equations and proofs that show how tubes work mathematically. Having these to me has been the icing on the cake to the other two books, but may or may not be your taste.
Sounds like you know your way around a tube circuit. So, depending on your budget, i suggest you get a vintage tube integrated amplifier, which is a tubed preamp and power amp in one chassis. There are a plethora of units from Fisher, Scott, EICO , Heathkit, for the well known brands, and many others as well. Rebuilding a unit can be rewarding in many ways, plus the vintage units retain their value, not like any equipment made now.
It may be a little off the path, but as I go along something that's been really educational was to buy a few "ordinary home audio" grade amps in need of repair and go through them with Jones' book at the reach. You can learn a lot about layout from something that was mass produced. Also a lot about cutting corners, which often means you can "restore" the amp to something better than was when new.
I got into tube amps back in 1989 by buying a Dynaco 70 from an audiophile friend. He was my only source for repair, so when after awhile, I took it on myself to fix the thing.
And then I started modifying - doing a lot of reading, making a few mistakes, but generally upgrading any number of vintage amplifiers with better parts and even better circuits.
It was that education that started me on the DIY path - and again I made a few mistakes since this was early internet days, but overall I had some successes. I made a 71A linestage back then, a push-pull 6B4G amplifier, and a single-ended 2A3 amp that drove a pair of Stephens Tru-Sonic drivers inside of a DIY cabinet.
I've since moved away from triodes (the Sound Practices days) and onto pentodes!
Words of wisdom:
Amps are the most expensive to build: iron and chassis are the big costs.
Preamps are the most difficult to build, specifically phono preamps since grounding issues, noise, hum, are more likely to rear their ugly heads.
Chassis is the most infuriating part of DIYing - top-plate on the wooden chassis is the most popular. I like to use Front Panel Express for creating the plates. These days I use metal chassis since my carpenter friend moved to another state.
Buy lots of solid-core 18awg wire in different colors - at least green, black, and red. You can never have enough of the stuff around.
Test equipment: bare minimum is a high quality multi-meter. That will allow you to troubleshoot the majority of tube circuit issues. A scope and signal generator is the next step up for trickier problems.
And then I started modifying - doing a lot of reading, making a few mistakes, but generally upgrading any number of vintage amplifiers with better parts and even better circuits.
It was that education that started me on the DIY path - and again I made a few mistakes since this was early internet days, but overall I had some successes. I made a 71A linestage back then, a push-pull 6B4G amplifier, and a single-ended 2A3 amp that drove a pair of Stephens Tru-Sonic drivers inside of a DIY cabinet.
I've since moved away from triodes (the Sound Practices days) and onto pentodes!
Words of wisdom:
Amps are the most expensive to build: iron and chassis are the big costs.
Preamps are the most difficult to build, specifically phono preamps since grounding issues, noise, hum, are more likely to rear their ugly heads.
Chassis is the most infuriating part of DIYing - top-plate on the wooden chassis is the most popular. I like to use Front Panel Express for creating the plates. These days I use metal chassis since my carpenter friend moved to another state.
Buy lots of solid-core 18awg wire in different colors - at least green, black, and red. You can never have enough of the stuff around.
Test equipment: bare minimum is a high quality multi-meter. That will allow you to troubleshoot the majority of tube circuit issues. A scope and signal generator is the next step up for trickier problems.
If you have already built guitar amps, maybe you are ready to consider point to point wiring your own. Sounds like you aren't ready to do your own design, but some small amount of modding existing proven designs may be very worthwhile.
Suggest studying the Mullard 5-20 and Eli Duttman's El Cheapo. Definitely go with a simple depletion mode FET current source. Capable of driving a wide range of speakers; lots of threads on this site regarding those amps.
Don't get distracted with exotic parts, and select low cost but linear triodes. Nothing wrong with strapping pentodes. UL is advised only if you really need the power.
Suggest studying the Mullard 5-20 and Eli Duttman's El Cheapo. Definitely go with a simple depletion mode FET current source. Capable of driving a wide range of speakers; lots of threads on this site regarding those amps.
Don't get distracted with exotic parts, and select low cost but linear triodes. Nothing wrong with strapping pentodes. UL is advised only if you really need the power.
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