Hi!
I fully agree with the other posters. If on a tight budget, 300B is the worst choice you can make. 300Bs do sound sublime if paired with high quality power supply, filament supply and parts. But at a lower budget much better sound quality can be achieved with cheaper tubes. This leaves budget for higher grade transformers and other parts.
Besides. I would be vary of a supplier who offers a $75 kit as 'luxury'. Then lists famous brand capacitors in the parts list, but shows some generic chinese 'no-brand' caps on the photos.
But most importantly I would be worried about the tightly packed parts and the high wattage resistors (presumably the cathode resistors) closely surrounded by electrolytics. Those cathode resistors will generate quite some heat and will fry and dry out the elcaps quickly.
BR
Thomas
I fully agree with the other posters. If on a tight budget, 300B is the worst choice you can make. 300Bs do sound sublime if paired with high quality power supply, filament supply and parts. But at a lower budget much better sound quality can be achieved with cheaper tubes. This leaves budget for higher grade transformers and other parts.
Besides. I would be vary of a supplier who offers a $75 kit as 'luxury'. Then lists famous brand capacitors in the parts list, but shows some generic chinese 'no-brand' caps on the photos.
But most importantly I would be worried about the tightly packed parts and the high wattage resistors (presumably the cathode resistors) closely surrounded by electrolytics. Those cathode resistors will generate quite some heat and will fry and dry out the elcaps quickly.
BR
Thomas
For a tight budget and want to try out tube amp with point to point soldering, try something like this
Class A Single Ended EL34 5Z3P Tube Audio Amplifier 13W 2 Hifi Valve AMP DIY KIT | eBay
Yes the component may not be high quality, but the sound is reasonable.
You can mod it later by changing higher quality parts.
Class A Single Ended EL34 5Z3P Tube Audio Amplifier 13W 2 Hifi Valve AMP DIY KIT | eBay
Yes the component may not be high quality, but the sound is reasonable.
You can mod it later by changing higher quality parts.
I forgot to add a quite good instruction can be found:
Tube Amplifier - 5Z3P, 6N9P, EL34
Hope this help.
Tube Amplifier - 5Z3P, 6N9P, EL34
Hope this help.
Thank you all very much for valuable opinions, ideeas, links ...
I have read a lot these days about those tube amps, again I am not an electronist but also I am not complete outside ... anyway I have to consider I am not prepared for really DIY a tube amp, maybe better to modify / upgrade an ready made amp!
I have to agree that 300B SE project is not for me in this moment. As someone mentioned already, another search lead me to a KT88 SE Class A already made/soldered amp with affordable price:
HiFi KT88 Tube Amplifier Single Ended Classe A Audio Tube Amplifier 16W X2 | eBay
with intention to mods/tweaks later when time and money will allow:
- better output transformers
- better tubes
- changing capacitors ...
The Class A SE EL34 kit is also very tempting and price firendly
I dont know exactly why but I feel I would go for KT88 SE ... !? Am I wrong?
I have read a lot these days about those tube amps, again I am not an electronist but also I am not complete outside ... anyway I have to consider I am not prepared for really DIY a tube amp, maybe better to modify / upgrade an ready made amp!
I have to agree that 300B SE project is not for me in this moment. As someone mentioned already, another search lead me to a KT88 SE Class A already made/soldered amp with affordable price:
HiFi KT88 Tube Amplifier Single Ended Classe A Audio Tube Amplifier 16W X2 | eBay
with intention to mods/tweaks later when time and money will allow:
- better output transformers
- better tubes
- changing capacitors ...
The Class A SE EL34 kit is also very tempting and price firendly
I dont know exactly why but I feel I would go for KT88 SE ... !? Am I wrong?
KT88 provide higher power output than EL34. Just google around on KT88 vs EL34 and form your own interpretation of people views. I went for EL34 as I found EL34 is cheaper, less demand on power (current). But if you get an amp kit, make sure you ask the specification of the Power Supply Transformer to see if you can make use of it if you decide to change your circuit as I believe this is your hobby / learning project on tube amp.
I will try an EL34 SE kit from analogmetric, their recommended power transformer, tubes & choke coil , but for OT I will go for Toroidy TTG-EL34SE ...
I will use these parts to build a power amp, learn, tweak, mods ... but after a while I would like to try also with KT88 ... I hope only some small changes are to be done to acomodate KT88
But first I will use and learn from initial EL34 kit ... really curious to hear it !
I will use these parts to build a power amp, learn, tweak, mods ... but after a while I would like to try also with KT88 ... I hope only some small changes are to be done to acomodate KT88
But first I will use and learn from initial EL34 kit ... really curious to hear it !
Biscu, glad you start on something.
My understanding, in general with fix bias, interchange between
- KT88 & EL34 is cathode resistor change (KT88 requires more current)
- EL34 & 6L6 is gate resistor change (some other people might just swap without changing anything).
This is only my 2cents, other people may disagree, as it all depends on the schematic design. It may be beneficial if you ask analogmetric what need to change if you want to use KT88 & also ask if you want to swap between 6SN7 & 6SL7.
My understanding, in general with fix bias, interchange between
- KT88 & EL34 is cathode resistor change (KT88 requires more current)
- EL34 & 6L6 is gate resistor change (some other people might just swap without changing anything).
This is only my 2cents, other people may disagree, as it all depends on the schematic design. It may be beneficial if you ask analogmetric what need to change if you want to use KT88 & also ask if you want to swap between 6SN7 & 6SL7.
Thank you very much cl1238 ... it counts not to feel alone! Since is a real new adventure this one and money arent "flowing in my yard" I am a little afraid about what we'll be ... nice to have someone at least listening to you.
I assume I will receive with the kit also the schematic, than I will scan and put it here, for others if curious, and too receive some advices for upgrades, mods or KT88 modifications ...
Seems their power transformer (285-0-285V) is low for KT88, but the question is: the rest of amplifier can accept 375-0-375V !? If yes that means I will have to change the power transformer, if not, maybe I have also to change some parts in the schematics for 375V ... we will see. First I will start with basic EL34 kit ...
For those about to Rock, we salute You!
BTW any opinions about heavy metal music and power tube amplifiers? Is love or hate? I dont expect to hear something in the middle
... it counts not to feel alone! Since is a real new adventure this one and money arent "flowing in my yard" I am a little afraid about what we'll be ... nice to have someone at least listening to you.I assume I will receive with the kit also the schematic, than I will scan and put it here, for others if curious, and too receive some advices for upgrades, mods or KT88 modifications ...
Seems their power transformer (285-0-285V) is low for KT88, but the question is: the rest of amplifier can accept 375-0-375V !? If yes that means I will have to change the power transformer, if not, maybe I have also to change some parts in the schematics for 375V ... we will see. First I will start with basic EL34 kit ...
For those about to Rock, we salute You!
BTW any opinions about heavy metal music and power tube amplifiers? Is love or hate? I dont expect to hear something in the middle
A solid state rectifier with a capacitor input supply ( CLC ideally ) would give you even more than 375V so you could go for cheaper ( higher dc resistance ) chokes and get your 375V. Tubes vs solid state ( on your question about heavy metal ) - they can both sound bad or very good, depending on how you design the amp, not that much on the type of amplification device employed.
Personally, I find EL34 to sound sweeter in the midrange and the KT88 to be bigger sounding and somewhat more analytical.
Personally, I find EL34 to sound sweeter in the midrange and the KT88 to be bigger sounding and somewhat more analytical.
So, after hard battles and long time the Analogmetric kit with EL34 SE arrived to me ... and here starts the fun:
- the transport is quite expensive so the total bill is no longer such a big deal ... maybe because of the weight of power transformer and chocke!
- the customs were so happy to charge me with 6% and 20% for VAT , to all amount (meaning including the transport cost and the parts value) so now we can say it become a little expensive EL34 SE ...
- the ordered Shuguang tubes (EL34 and 6SN7) are missing from the package! after many emails, finaly someone responded and told me they will ship to me the tubes, when and how did not told me even if I specificaly asked. Anyway I already paid transport, customs tax and VAT for those missing tubes, so what will happen when they will arrive again in customs ... !?
- they are not paying attention to details, making small mistakes and if they answer to emails is after a long time and incomplete, a few words and ready ... sad, because on their web-page are a lot of interesting kits and parts
- the PCB board looks nice and strong, the parts are OK, good quality and measured in specifications, but ... after solder almost all resistors, only 2 left and I need your help!
In the attached schematics the R11 and R11B are indicated for 100 Ohm and the same indication is in the parts list I have received, but the 2 resistors that remain to be soldered are 100 Kohm (actualy 95 Kohm).
Please advice, what value should be R11 (and R11B) 100 ohm or 100 kohm? for this schematic to work properly ...
- the transport is quite expensive so the total bill is no longer such a big deal ... maybe because of the weight of power transformer and chocke!
- the customs were so happy to charge me with 6% and 20% for VAT , to all amount (meaning including the transport cost and the parts value) so now we can say it become a little expensive EL34 SE ...
- the ordered Shuguang tubes (EL34 and 6SN7) are missing from the package! after many emails, finaly someone responded and told me they will ship to me the tubes, when and how did not told me even if I specificaly asked. Anyway I already paid transport, customs tax and VAT for those missing tubes, so what will happen when they will arrive again in customs ... !?
- they are not paying attention to details, making small mistakes and if they answer to emails is after a long time and incomplete, a few words and ready ... sad, because on their web-page are a lot of interesting kits and parts
- the PCB board looks nice and strong, the parts are OK, good quality and measured in specifications, but ... after solder almost all resistors, only 2 left and I need your help!
In the attached schematics the R11 and R11B are indicated for 100 Ohm and the same indication is in the parts list I have received, but the 2 resistors that remain to be soldered are 100 Kohm (actualy 95 Kohm).
Please advice, what value should be R11 (and R11B) 100 ohm or 100 kohm? for this schematic to work properly ...
I will try an EL34 SE kit from analogmetric, their recommended power transformer, tubes & choke coil , but for OT I will go for Toroidy TTG-EL34SE ...
I will use these parts to build a power amp, learn, tweak, mods ... but after a while I would like to try also with KT88 ... I hope only some small changes are to be done to acomodate KT88
But first I will use and learn from initial EL34 kit ... really curious to hear it !
First thing you need to know is whether the power trans is designed for 110/220 as is in China or 120vac as in USA. This can be critical to the longevity of your tubes and other components. Many kit sellers will not tell you outright so be sure to find out or you will see your tubes being used up in a matter of months or hours as the voltages will all be way over the design specifications. good luck
ps. i noticed that you are in Europe so my warning may not apply. If not have at it!
pps. i also noticed in the provided schematic that there is no "grid stopping resistor" on the input of the el34. Almost every tube amp uses grid stoppers for the power tube to prevent oscillation. Orinarily, it is fairly easy to put one in on pins 5 and 6 of the el34 but since you are using a pcb i am not sure how you can work around that. good luck
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.