barrymclark Posted September 29, 2012 Share Posted September 29, 2012 Well, getting the bits together anyways. I got an unexpected bonus at work and, while not a crapload of money, it is enough to get the ball rolling on aquiring the components. For those who might remember some threads some time ago, this will be, basically, a heavyweight Champ. It will be a 30w SE Class A with a KT88 in the power section and a single 12ax7 in the pre. The rectifier will be a socketed solid state. Speakers will likely be a pair of Eminence RedCoat series 12" speakers. Black tweed (still looking for a distributor of this) and laquered tweed will be the likely motif. The first thing or things ordered will likely be the Chassis, board and resistors, caps, sockets and the little fiddly bits. The tubes/PT/OT will have to come later as money permits. The cabinets for the head and speaker cabs will have to be made by someone else. I don't have the confidence there as I do with a solder gun. Should be fun. Hopefully nothing bad happens or the wife finds something 'better' to do with the money. Link to comment Share on other sites More sharing options...
big bob Posted September 30, 2012 Share Posted September 30, 2012 Will a single kt88 give up 30 watts ? Link to comment Share on other sites More sharing options...
212Mavguy Posted September 30, 2012 Share Posted September 30, 2012 not without distorting monstrously if at all...in a single ended amp with one power tube. More like 15-18-ish Class A watts plus extra after hitting it hard enough.. Link to comment Share on other sites More sharing options...
barrymclark Posted September 30, 2012 Author Share Posted September 30, 2012 Correct me if I\'m wrong but I believe it is capable of 25w clean on its own. Link to comment Share on other sites More sharing options...
barrymclark Posted September 30, 2012 Author Share Posted September 30, 2012 In fact, our own KBP810 had a 25w single KT88 amp. Link to comment Share on other sites More sharing options...
barrymclark Posted September 30, 2012 Author Share Posted September 30, 2012 What inspired me here was actually folks that build stereo amps using a single KT88 a side for 20w per side. In all honesty, I would likely never get the volume knob past halfway on the dial. So I am not terribly concerned about what it will do beyond that. But yeah, beyond the 20w.... I expect it to get nothing but nasty. I am just wanting reasonably old school clean up to a reasonably loud level. SE Class A even at 20w will about cut someone\'s head off. Sent from my iPad using Forum Runner Link to comment Share on other sites More sharing options...
H Posted September 30, 2012 Share Posted September 30, 2012 Well, getting the bits together anyways. Black tweed (still looking for a distributor of this) and laquered tweed will be the likely motif. The cabinets for the head and speaker cabs will have to be made by someone else. Good news May I make a suggestion for you on the cab builder? Have a chat with Jeff McMurray at Bandmate USA in WI. He is an amazing cabinet builder with great prices. Google the company name and you'll find great reviews if his work on TGP and other guitar forums. Tell him Howard the Limey recommended him http://www.theguitararmory.com/ Link to comment Share on other sites More sharing options...
barrymclark Posted September 30, 2012 Author Share Posted September 30, 2012 Good news May I make a suggestion for you on the cab builder? Have a chat with Jeff McMurray at Bandmate USA in WI. He is an amazing cabinet builder with great prices. Google the company name and you\'ll find great reviews if his work on TGP and other guitar forums. Tell him Howard the Limey recommended him http://www.theguitararmory.com/ Thanks! I will be sure to mention that Howard the Limey referred Barry the Yank to him. haha. Sent from my iPad using Forum Runner Link to comment Share on other sites More sharing options...
barrymclark Posted September 30, 2012 Author Share Posted September 30, 2012 What I am looking to get performance wise is about 15w-20w unclipped and just have the 30w tranny for headroom. Make no mistake, this little amp will dwarf a drummer especially since I am going to run it into two very sensitive Eminence 12\" speakers. SCREAMING loud. Sent from my iPad using Forum Runner Link to comment Share on other sites More sharing options...
212Mavguy Posted October 1, 2012 Share Posted October 1, 2012 What I am looking to get performance wise is about 15w-20w unclipped and just have the 30w tranny for headroom. Make no mistake, this little amp will dwarf a drummer especially since I am going to run it into two very sensitive Eminence 12\" speakers. SCREAMING loud. Sent from my iPad using Forum Runner Now were'e talking! The 30w tranny will provide more than just headroom, Barry, it is the absolute foundation of the tone you'll be getting, it is the heart of your amp, it is responsible for interpreting and translating the circuit's output to something the speakers can work with. Don't be surprised when you find out how loud it is, or how hard hitting it will be when you dig into a string with some oomph. Regarding wattage ratings, the figures quoted that seem high are for a class AB push pull topology, not class A single ended. Every power tube often used in guitar amps has a spec sheet of what it can do. Included are ratings at different voltages and operating classes. The operating class has a huge effect on wattage ratings for a given tube type. For instance, a pair of 6v6's gives up 14-20-ish watts in a push pull circuit, but in a single ended Fender Champ, operating at a very high b+ (375?)voltage BTW, that single 6v6 only gives up 6 watts according to the builders. The data sheet for 6v6gt will reflect the tendencies of these numbers. That one tube has to push the signal through both sides of the waveform, in a PP design the work is shared between the tubes, each responsible for one half of the waveform instead of the whole. I'm absolutely thrilled for you! The simplest preamp circuits with the kind of parts selection and lead dress that only a handwired amp can provide are going to be just plain inspiring to play through, plus as an added, significant GAS risk exposure, this amp will respond very vocally to vintage tube and also speaker rolling, a very honest platform it will be! Don't be surprised playing bass through it for a small room through big speakers, that big output tranny will enable it to do just fine. Link to comment Share on other sites More sharing options...
barrymclark Posted October 1, 2012 Author Share Posted October 1, 2012 Now were'e talking! The 30w tranny will provide more than just headroom' date=' Barry, it is the absolute foundation of the tone you'll be getting, it is the heart of your amp, it is responsible for interpreting and translating the circuit's output to something the speakers can work with. Don't be surprised when you find out how loud it is, or how hard hitting it will be when you dig into a string with some oomph. Regarding wattage ratings, the figures quoted that seem high are for a class AB push pull topology, not class A single ended. Every power tube often used in guitar amps has a spec sheet of what it can do. Included are ratings at different voltages and operating classes. The operating class has a huge effect on wattage ratings for a given tube type. For instance, a pair of 6v6's gives up 14-20-ish watts in a push pull circuit, but in a single ended Fender Champ, operating at a very high b+ (375?)voltage BTW, that single 6v6 only gives up 6 watts according to the builders. The data sheet for 6v6gt will reflect the tendencies of these numbers. That one tube has to push the signal through both sides of the waveform, in a PP design the work is shared between the tubes, each responsible for one half of the waveform instead of the whole. I'm absolutely thrilled for you! The simplest preamp circuits with the kind of parts selection and lead dress that only a handwired amp can provide are going to be just plain inspiring to play through, plus as an added, significant GAS risk exposure, this amp will respond very vocally to vintage tube and also speaker rolling, a very honest platform it will be! Don't be surprised playing bass through it for a small room through big speakers, that big output tranny will enable it to do just fine.[/quote'] Thanks! Since the demise of the KBP build of the Starlite, I have been pondering its build ever since. I really wanted an amp that would tell no lies about the player. I believe I am on to it here. What was funny was as I poured over the schematics of my favorite amps, I noticed the shocking similarities between some of the main components. Going over those and and talking shop with Brian here and there has really helped me cement the plan for it. I have no idea what the cabinetry will cost but the amp itself won't be a killer price wise. The KT88, speakers and trannies will be the megachunks of price. Especially that 30w. Brian said he found some, I think they were American Classics (maybe Edcor), that would fit the standard Champ chassis (the OT would require a little modification). I'll look closer at that when I actually start purchasing parts. Sent from my iPad using Forum Runner Link to comment Share on other sites More sharing options...
barrymclark Posted October 2, 2012 Author Share Posted October 2, 2012 Now were'e talking! The 30w tranny will provide more than just headroom' date=' Barry, it is the absolute foundation of the tone you'll be getting, it is the heart of your amp, it is responsible for interpreting and translating the circuit's output to something the speakers can work with. Don't be surprised when you find out how loud it is, or how hard hitting it will be when you dig into a string with some oomph. Regarding wattage ratings, the figures quoted that seem high are for a class AB push pull topology, not class A single ended. Every power tube often used in guitar amps has a spec sheet of what it can do. Included are ratings at different voltages and operating classes. The operating class has a huge effect on wattage ratings for a given tube type. For instance, a pair of 6v6's gives up 14-20-ish watts in a push pull circuit, but in a single ended Fender Champ, operating at a very high b+ (375?)voltage BTW, that single 6v6 only gives up 6 watts according to the builders. The data sheet for 6v6gt will reflect the tendencies of these numbers. That one tube has to push the signal through both sides of the waveform, in a PP design the work is shared between the tubes, each responsible for one half of the waveform instead of the whole. I'm absolutely thrilled for you! The simplest preamp circuits with the kind of parts selection and lead dress that only a handwired amp can provide are going to be just plain inspiring to play through, plus as an added, significant GAS risk exposure, this amp will respond very vocally to vintage tube and also speaker rolling, a very honest platform it will be! Don't be surprised playing bass through it for a small room through big speakers, that big output tranny will enable it to do just fine.[/quote'] Btw, what is speaker rolling? Never heard that term. Sent from my iPad using Forum Runner Link to comment Share on other sites More sharing options...
Kuz Posted October 2, 2012 Share Posted October 2, 2012 With 2 x 12s this baby is not going to be easy on the back, but I bet it will sound great. Link to comment Share on other sites More sharing options...
212Mavguy Posted October 2, 2012 Share Posted October 2, 2012 Same as tube rolling, but speakers have more effect on the tone than tubes do. I have found a custom builder on ebay whose stuff kills modern production for less $$. Also have found a couple vintage unknown to guitar player Pioneer brand Japanese speakers that kill any Jensen for the tweed tone, they are much better made and go for pennies on the Jensen dollar. Link to comment Share on other sites More sharing options...
barrymclark Posted October 3, 2012 Author Share Posted October 3, 2012 Same as tube rolling' date=' but speakers have more effect on the tone than tubes do. I have found a custom builder on ebay whose stuff kills modern production for less . Also have found a couple vintage unknown to guitar player Pioneer brand Japanese speakers that kill any Jensen for the tweed tone, they are much better made and go for pennies on the Jensen dollar.[/quote']ok, what's tube rolling? If I am left cold by the Eminence, and I generally love Eminence, then I will definitely hit you up on that maker. Sent from my iPad using Forum Runner Link to comment Share on other sites More sharing options...
barrymclark Posted October 3, 2012 Author Share Posted October 3, 2012 Same as tube rolling' date=' but speakers have more effect on the tone than tubes do. I have found a custom builder on ebay whose stuff kills modern production for less . Also have found a couple vintage unknown to guitar player Pioneer brand Japanese speakers that kill any Jensen for the tweed tone, they are much better made and go for pennies on the Jensen dollar.[/quote'] gotta say tho, i really dug the Celestion pairing in the z-best. Vintage 30 and G12H30. Sent from my iPad using Forum Runner Link to comment Share on other sites More sharing options...
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