DIY Audio Projects Forum

Hey wilson, welcome to the forum.

What sort of projects are you interested in.

Cheers

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[ DIY Mains AC Power Cable Cord ] - [ K-12 Tube Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]

You have been assimilated.... resistance was futile @_o

Welcome!

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-= Gregg =-
* Ratings are for transistors - tubes have guidelines*
Home: GeeK ZonE
Work: Classic Valve Design

Well, the cathode resistance was futile, the grid resistance is usually pretty substantial.

Welcome to the fourms.

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Matt
It's all about the Glass!
http://www.CascadeTubes.com

Thanks, all. I just bought a Kenwood KA-7100 and a Scott 299B. These will alternate as my everyday system. I was shopping for 2 channel receivers and just fell in love with these two pieces. Now I need to find the right speakers to pair them with. I'm a little worried about overdriving the Scott but have no basis for my concern. I'm sure these will need some work and I'll have more specific questions later. For now, though, can you folks recommend speakers or point me toward the appropriate specs for these two units? There is an old Scott endtable style floorstander at my local thrift but it's a single and I don't know how it would sound. It would make a very cool stand for that amp, though. I've been looking at >90db speakers with big cabinets thinking that's the way to pull a big sound out with killing the amp. I can spend about $500 on speakers. Any advice here?

This system will be in a dedicated 9'x11' listening room. Tiny but all mine. The only input will be from my laptop and i-things . I'm also shopping for a DAC too but not sure if that's a dyi thing. Much of my listening will be audience recordings of rock shows.

Can't wait to read your thoughts!

Are you looking to build speakers or buy?

There are part DAC kits available. You can buy a finished DAC board and then you can mount them in an enclosure of your choice. I'm using a Musical Fidelity V-DAC II that I am pretty happy with.

Cheers

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[ DIY Mains AC Power Cable Cord ] - [ K-12 Tube Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]

Hi, Welcome to the forum. Check out the projects on the Parts Express speaker builder section. They have several and the components are often inexpensive. I shop at thrift stores and snagged a pair of Klipsch KG4s for $80, perfect shape, also a pair of Altec Lansing 1010s for $75. Both are high sensitivity small floor standers or it you choose rather large bookshelf ones.

Good listening
Bruce

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Some of my DIY Tube Amplifier Projects:

• PoddWatt: 5751 / EL84 Push-Pull DIY Tube Amplifier Project
• OddBlocks: KT88 Push-Pull DIY Tube Amplifiers (Mono Blocks)
• ForeWatt: ECC802S (12AU7 / ECC82) DIY Tube Preamplifier Project
• GrooveWatt: Tube (Valve) RIAA Phono Preamplifier Project

Hi, Welcome to the forum and your interest in tube audio. For raw power solid state amps can't be beat. However most listening is done at significantly lower power levels. A lot depends on you choice of speakers. High sensitivity ones require much less power than low sensitivity one. The difference in power needed to get a certain loudness can be well over 10 times as much. Again tubes amps seem to sound louder - although they are not. Most of the difference is in how they behave when over driven. They usually compress the peaks rather than clip them as is typical of most solid state amps. Compression is not particularly obvious in small amounts, clipping in nearly any amount is horrible sounding. The KT88 amps in the project are quite sufficient for speakers with sensitivities of 90 db/watt or more. They will provide as much sound as you can want. The bass response goes to sub audio frequencies (typically to 10 HZ flat). If you need more power I have a project pending (the amps already exist) using KT120 tubes. It will deliver 45 watts RMS. It is class A U/L like the other amps. Very powerful and excellent sounding. There are some threads on this forum about it. PM me if you want some details.

Good listening
Bruce

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Some of my DIY Tube Amplifier Projects:

• PoddWatt: 5751 / EL84 Push-Pull DIY Tube Amplifier Project
• OddBlocks: KT88 Push-Pull DIY Tube Amplifiers (Mono Blocks)
• ForeWatt: ECC802S (12AU7 / ECC82) DIY Tube Preamplifier Project
• GrooveWatt: Tube (Valve) RIAA Phono Preamplifier Project

Hello everyone!

My name is Alexander and i am from Lithuania
I started DIY when I was around 11 years old and since then I always want to build something new. Your page projects encouraged me to go further and start making tube amps. I hope to have a great time here with all you audio enthusiasts!

Cheers,
Alexander

Hi, An update to my earlier post. Something I overlooked. With all the KT88 amps sold on the commercial side (many) of my projects, we now recommend the JJ KT88s over the Gold Lions. We discontinued supplying GLs as standard. Not because of cost as they are fairly close in that area, but because we have had two of the GLs go soft and refuse to balance after about 2 years of service. None of the JJ tubes to my knowledge have had this happen. My original set of JJs is still going strong after nearly 4 years and many thousands of hours. In the design of the amps one thing I consider is long tube life. I expect a typical user should get at least 5000 hours and more likely 8-10000 hours of life before replacement is needed.

For anyone who didn't pick up on it before, we also had problems with EH KT88s. Matched pairs would not balance well and stay balanced. I don't believe that they are defective, just some small aspect of their design or construction causes the problem. As for the GL KT88s, perhaps they are not designed to last as long as the JJs. I don't know. I just wanted to report this issue so that the diyer doesn't get a big surprise after a few 1000 hours of use. BTW, while I will not publicly say who, but we have found two main tube supplier companies that do not either carefully screen or properly test tubes in matched pairs. So buyer beware if you get some that don't behave well, holler and get replacements. Well matched output tubes will balance easily and stay that way in the amps. Buy from reputable sources.

Good listening
Bruce

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Some of my DIY Tube Amplifier Projects:

• PoddWatt: 5751 / EL84 Push-Pull DIY Tube Amplifier Project
• OddBlocks: KT88 Push-Pull DIY Tube Amplifiers (Mono Blocks)
• ForeWatt: ECC802S (12AU7 / ECC82) DIY Tube Preamplifier Project
• GrooveWatt: Tube (Valve) RIAA Phono Preamplifier Project

New to the forum. I live in Maine and work lobstering most of the year but have a lot of down time in the winter months, perfect for playing a few gigs with the guitar and heating up the solder iron for some mods on an old tube amp. I hope to learn from some of the great minds on here. It seemed like every time I googled a question for a project it sent me here, so I figured I'd join in the fun!