I have been thinking abiut building a tube amp. recently i heard my brother in law's consonance (in singapore). it left me not so much impressed (maybe the spendor speakers had something to do with this).
The other part of tubes that worries me is the large audio trannies. building good audio trannies from what i gather is an art that is dying.
i live in india most of the year and getting these trannies in india are hell. importing them is crazier they weight 3-4 kgs per pc if not more. that is a lot of iron.
as a tube newbie living in a warm country i guess my best bet is a parallel push pull el 34 (quad tubes). it is relatively simple and can drive my 4 ohm speakers 87db speakers to about 95db and still have enough headroom.
are there any tubes amps that do not use output transofrmers (OTL) that can drive low impedance loads (I can redesign my speakers to 8 ohms)? How much power do they put out? are they simple (as simple as the EL84 and EL34 ckts i have seen on the net)?
The other part of tubes that worries me is the large audio trannies. building good audio trannies from what i gather is an art that is dying.
i live in india most of the year and getting these trannies in india are hell. importing them is crazier they weight 3-4 kgs per pc if not more. that is a lot of iron.
as a tube newbie living in a warm country i guess my best bet is a parallel push pull el 34 (quad tubes). it is relatively simple and can drive my 4 ohm speakers 87db speakers to about 95db and still have enough headroom.
are there any tubes amps that do not use output transofrmers (OTL) that can drive low impedance loads (I can redesign my speakers to 8 ohms)? How much power do they put out? are they simple (as simple as the EL84 and EL34 ckts i have seen on the net)?
I have a Consonance EL34 amp that was built from a kit. You are right that the sound is not as you would like it. I have done a lot of work upgrading it and it had improved by leaps and bounds.
The circuit is very simple, and all you need really is to change the cheap components on the board into better grade components for drastic improvements to be heard.
Top of the list, just rid of the stock 12AX7 in the preamp. A much better tube would be the 6922 ( my opinion ). You can compensate for the loss in gain by adding a good cap to the cathode resistor of the preamp, which improved details, soundstage, and whole lot of body to the sound. You need some surgery for this mod as the 12AX7 are 12.6V filament voltage as compared to the 6.3V.
Finally, triode mode connections at output stage reduces power but improves clarity. Chaging the cheap reisitors to Kiwame and the MKPs to PIOs will give another quantum improvement.
I like making circuits and see almost instant results. No joy for me in making chasis etc. Hence moding is a lot more fun. I know nothing on tubes theory, I just know enough not to smoke anything, and then depend on my ears to instruct what stays and what goes.
KT88 sucks in my opinion.
The circuit is very simple, and all you need really is to change the cheap components on the board into better grade components for drastic improvements to be heard.
Top of the list, just rid of the stock 12AX7 in the preamp. A much better tube would be the 6922 ( my opinion ). You can compensate for the loss in gain by adding a good cap to the cathode resistor of the preamp, which improved details, soundstage, and whole lot of body to the sound. You need some surgery for this mod as the 12AX7 are 12.6V filament voltage as compared to the 6.3V.
Finally, triode mode connections at output stage reduces power but improves clarity. Chaging the cheap reisitors to Kiwame and the MKPs to PIOs will give another quantum improvement.
I like making circuits and see almost instant results. No joy for me in making chasis etc. Hence moding is a lot more fun. I know nothing on tubes theory, I just know enough not to smoke anything, and then depend on my ears to instruct what stays and what goes.
KT88 sucks in my opinion.
OTL's
Hi Navin,
You might be right about PP amps being best for this place. OTL's can sometimes be a problem and with difficulty in getting replacement speaker drivers and tubes ( not to mention cost ) , it might best be avoided. I read something on the net about many of them just breaking down. I guess the speaker goes along with it. I also get the impression from various posts that they can be fussy amplifiers.
PP on the other hand seems to be far more reliable. Many swear by SE's but other think most are too soggy and of course low powered. I heard some SE's long ago and thought they were nice but didn't really critically evaluate them at the time. The bass limitations and limited power is enough for me to avoid them.
EL34's are very well regarded . Did you think of a triode like the 2A3 ? You could make a PP out of that. Power will not be too much . But it will be a true triode amp. Someone once said that they liked the 2A3's sound over the 300B . I guess this is hard to say because there are so many different manufacturers and so many implementations.
Cheers.
Ashok.
Hi Navin,
You might be right about PP amps being best for this place. OTL's can sometimes be a problem and with difficulty in getting replacement speaker drivers and tubes ( not to mention cost ) , it might best be avoided. I read something on the net about many of them just breaking down. I guess the speaker goes along with it. I also get the impression from various posts that they can be fussy amplifiers.
PP on the other hand seems to be far more reliable. Many swear by SE's but other think most are too soggy and of course low powered. I heard some SE's long ago and thought they were nice but didn't really critically evaluate them at the time. The bass limitations and limited power is enough for me to avoid them.
EL34's are very well regarded . Did you think of a triode like the 2A3 ? You could make a PP out of that. Power will not be too much . But it will be a true triode amp. Someone once said that they liked the 2A3's sound over the 300B . I guess this is hard to say because there are so many different manufacturers and so many implementations.
Cheers.
Ashok.
If you are a tube newbie I would recommend buying a vintage amp (perhaps two identical mono amplifiers) and restoring them with a few modern components.
You can pick up these amps reasonably cheaply, just search around, ask any old electronic repair stores, broadcasting studios etc. You can get some good bargains on eBay sometimes too.
I wouldn't worry too much about power, anything above 5W is enough for comfortable listening levels.
I would go for a PP EL34 or EL84 design, for decent power. If you want a cheap NOS alternative to an EL34, use an 807. They are closer to a 6L6 but are a grunty and cheap tube.
You can pick up these amps reasonably cheaply, just search around, ask any old electronic repair stores, broadcasting studios etc. You can get some good bargains on eBay sometimes too.
I wouldn't worry too much about power, anything above 5W is enough for comfortable listening levels.
I would go for a PP EL34 or EL84 design, for decent power. If you want a cheap NOS alternative to an EL34, use an 807. They are closer to a 6L6 but are a grunty and cheap tube.
cm said:
ok i just asked my BIL (he was in a meeting so i did not get much of an answer from him) he said he is using a EC88 for the pre and has Vishay resistors and solen caps. remember i said i did not like it. he seems happy. i found the bass a bit tubby (not tubey). i wil be doing a critical listening session tonight. more on dec 7th (PST)when i get my next connection.
for me an amp must feel like the better music halls i have heard (NCPA in bombay, Lincoln Center in NY, Bard College NY State, the music hall at Berkely CA, The Oper in Frankfurt, etc...)
no i have not considered the 2A3. last time i saw tubes was in 1977 (i went to a place called Radio Bhavan those of you from bombay might remember).
more later.
Suggestions
EL34, 2A3 have more distortion than KT88, but one has to move up a notch in design work to use a KT88. Vast experience is needed to use KT88, so it may not suitable for most people.
2A3, you have to contend with hum problems too.
I would suggest the EL34 in triode mode as your best solution. Price of tube and design is very reasonable for those on a budget.
Hope this helps.
EL34, 2A3 have more distortion than KT88, but one has to move up a notch in design work to use a KT88. Vast experience is needed to use KT88, so it may not suitable for most people.
2A3, you have to contend with hum problems too.
I would suggest the EL34 in triode mode as your best solution. Price of tube and design is very reasonable for those on a budget.
Hope this helps.
if output transformers and budget are a concern, you might consider building a tube preamp first, since they are cheaper and don't necessarily require OPTs.
It will be a good learning experience, the parts will be readily sourcable (relatively speaking). will inject tubed sound into your current system and you can either use the preamp with a tube amp if you decide to build one later or build the power tubes into the same chassis if you want and have the space.
other more knowledgable folks on this board can suggest circuits / tubes depending on the sound you are trying to achieve.
It will be a good learning experience, the parts will be readily sourcable (relatively speaking). will inject tubed sound into your current system and you can either use the preamp with a tube amp if you decide to build one later or build the power tubes into the same chassis if you want and have the space.
other more knowledgable folks on this board can suggest circuits / tubes depending on the sound you are trying to achieve.
navin said:
I understand that. But if you don't need the parts right now, have some money saved for them, and are patient, I find that opportunities spring from the most unlikely sets of circumstances. Tell everyone you know, especially non-audiophools that you're looking for old tube amplifiers, and people will tell you that their grandmother/friend/whatever has some old audio stuff in an attic, and lots of times, I've been given the parts for free. Or a friend/business aquaintance will gladly hump (iron) some back into the country for you from a trip overseas. People are often very helpful if you ask.
Spread the word and wait for the opportunity to present itself.
hey brother in law - howdy! not fair bro - dont remember you listening long enough to my consonance ella and spendors to form a judgement and certainly dont remember you listening to the setup from the sweet spot...hehehe...but quick to form judgement eh?
anyways you will have more time to listen to it when you come back here..hope youre having a great time
see you soon.
hi cm...would it be possible for you to list out the mods you did to the ella? cheers
anyways you will have more time to listen to it when you come back here..hope youre having a great time
see you soon.
hi cm...would it be possible for you to list out the mods you did to the ella? cheers
Mods I did to the Ella in order of impact to the sound:
1. chnage the Wima caps to Jensen PIO ( need deep pockets for this )
2. wired a toggle switch to switch between normal and triode mode connections. I mounted the toggle switch in between the EL34s.
3. Nichicon Muse 100ouF cap across the 470 ohm cathode resistor of the front end SRPP stage.
4. Choke for the PS ( this is wired differently from a conventional choke supply and hence the improvemetn I feel is only in the preamp stage.
5. biased the heaters at 50 Vs instead of floating ( in the original circuit ) for all the tubes. It should impreve treble but my mains is clean and hence not much impact.
6. bypass the 22uF cap of the preamp with 1u polyester directly between the 470 ohm and the plate of 6922. Better bass.
Next :
1. 6550 output stage.
2. step attenuator iso alps pot.
Hope this helps.
CM
1. chnage the Wima caps to Jensen PIO ( need deep pockets for this )
2. wired a toggle switch to switch between normal and triode mode connections. I mounted the toggle switch in between the EL34s.
3. Nichicon Muse 100ouF cap across the 470 ohm cathode resistor of the front end SRPP stage.
4. Choke for the PS ( this is wired differently from a conventional choke supply and hence the improvemetn I feel is only in the preamp stage.
5. biased the heaters at 50 Vs instead of floating ( in the original circuit ) for all the tubes. It should impreve treble but my mains is clean and hence not much impact.
6. bypass the 22uF cap of the preamp with 1u polyester directly between the 470 ohm and the plate of 6922. Better bass.
Next :
1. 6550 output stage.
2. step attenuator iso alps pot.
Hope this helps.
CM
homebrew TDA1541 Non OS DAC, with tube buffer made up of SRPP 6922. The buffer is a straight copy of the first stage of the Consonance, but with a lower bias current. The digital source - various, including a Pioneer CD player ( tapped the digital signals directly from servo chip or use SPDIF ), Philips VCD player again tapped signals, and a couple of computer CD ROM drive.
All my projects originated from a bet that I can make a 1000 British pound system that beats my friend's 5000 pound system. I am close but have not achieve the goal yet.
All my projects originated from a bet that I can make a 1000 British pound system that beats my friend's 5000 pound system. I am close but have not achieve the goal yet.
having so much experience with the ella consonance ihave a few questions:
1: do you recomend driving he consonace with a opamp based preamp (OP275) or do you recomend having a tube preamp too. i have 3 sources and a tape loop.
2. what were your first impressions when you built the stock ella consonance?
See i am interested in "going tubular" but the final goal is more real sound. my solid state and speakers after a lot of inkering still leave something missing.
1: do you recomend driving he consonace with a opamp based preamp (OP275) or do you recomend having a tube preamp too. i have 3 sources and a tape loop.
2. what were your first impressions when you built the stock ella consonance?
See i am interested in "going tubular" but the final goal is more real sound. my solid state and speakers after a lot of inkering still leave something missing.
would making this make more sense than making a full tube pre and/or power amps....i remember some time back there used to be a small battery powered ckt for fender strats to infuse "marshall" sound into sold state stacks. worked ok.
http://www.aksaonline.com/products/products_tlp.html
http://www.aksaonline.com/products/products_tlp.html
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