Thanks fredlock
They are bigger than the impression I had just from the pics...
You have quite a good thermal safety margin.
Tino
They are bigger than the impression I had just from the pics...
You have quite a good thermal safety margin.
Tino
Fredlock,
Nice job on the build. I like clear ends!
Where did you get the boards or did you fabricate them?
Thanks,
Dave
Nice job on the build. I like clear ends!
Where did you get the boards or did you fabricate them?
Thanks,
Dave
Skidave,
Yes, I fabricated them. I used Diptrace to make the layout. My layout was quite similar to Juma. I think there's like 4 to 5 pcb layout on the thread if you're looking for one.
Fred
Yes, I fabricated them. I used Diptrace to make the layout. My layout was quite similar to Juma. I think there's like 4 to 5 pcb layout on the thread if you're looking for one.
Fred
Thanks for the info. Again, project looks great.
I have not had time to follow this thread completely. Also, I have not tried to make any boards myself. I have to limit myself somewhere because of the lack of time. Is there more info about Diptrace on a site somewhere? How long was the process to make your boards?
Thanks,
Dave
I have not had time to follow this thread completely. Also, I have not tried to make any boards myself. I have to limit myself somewhere because of the lack of time. Is there more info about Diptrace on a site somewhere? How long was the process to make your boards?
Thanks,
Dave
Hi Skidave,
Don't do your own layout on diptrace or eagle if you haven't done it before, because it's time consuming. As what you mentioned, you have limited time but you want to build this amp. If I were you, I have to go for the existing layout on the link below and buy a press and peel paper, print the layout by Spind which is on adobe format on the press and peel paper, iron it on the pcb, etch it with etching solution, drill it and there you go, you're ready to solder the components. If you want to prevent the pcb from oxidation, you can buy a laquer varnish on a spray can to coat it. If you need more help, you can go to this link in you tube, http://www.youtube.com/watch?v=Q6WJqjVleG0&feature=related
http://www.diyaudio.com/forums/showthread.php?postid=1536556#post1536556
Hope this help.
Good luck,
Fred
Don't do your own layout on diptrace or eagle if you haven't done it before, because it's time consuming. As what you mentioned, you have limited time but you want to build this amp. If I were you, I have to go for the existing layout on the link below and buy a press and peel paper, print the layout by Spind which is on adobe format on the press and peel paper, iron it on the pcb, etch it with etching solution, drill it and there you go, you're ready to solder the components. If you want to prevent the pcb from oxidation, you can buy a laquer varnish on a spray can to coat it. If you need more help, you can go to this link in you tube, http://www.youtube.com/watch?v=Q6WJqjVleG0&feature=related
http://www.diyaudio.com/forums/showthread.php?postid=1536556#post1536556
Hope this help.
Good luck,
Fred
f5 amp
Thanks Nelson that fixed the oscillation problem, but i am still puzzeld by the ofset when under identical layout and testing conditions the other board d0es not change the ofset.The only difference is, one has fairchild and one has IRF output devices ..
Thanks Nelson that fixed the oscillation problem, but i am still puzzeld by the ofset when under identical layout and testing conditions the other board d0es not change the ofset.The only difference is, one has fairchild and one has IRF output devices ..
I want to make some of boards with some copper clad FR4 but not sure how thick the copper should be. Can you guys suggest a thickness for me? I was considering 2oz but really, I am not sure if this is enough or overkill. I will be buying alot of this so I can make many different designs and I want to have enough copper to handle most amps and PSUs. I know thats vague. I just want an all around good measure of safety. I will use these for Nelsons stuff as well as chip amps. Thinking of making the My_Ref_C.
Hope someone can help.
Thanks
Uriah
Hope someone can help.
Thanks
Uriah
Great 🙂 Thanks Mr. Pass.
Uriah
just got these and will use .5oz stuff for any preamps
http://cgi.ebay.com/20-lbs-Copper-C...Z4660QQcmdZViewItemQQ_trksidZp1742.m153.l1262
Thanks again
Uriah
just got these and will use .5oz stuff for any preamps
http://cgi.ebay.com/20-lbs-Copper-C...Z4660QQcmdZViewItemQQ_trksidZp1742.m153.l1262
Thanks again
two newbie questions re F5
1) Is it possible to raise the F5's input impedance so as to make it even friendlier to a delicate tube preamp? (Mine likes a 470k ohm input impedance on an amp). What would be the effect on the F5's performance of doing this?
2) Could one use paper-in-oil caps in the power supply? I know a diy'er who swears by them, even in the power supply, for imparting a rich, full, warm sound.
Thanks.
1) Is it possible to raise the F5's input impedance so as to make it even friendlier to a delicate tube preamp? (Mine likes a 470k ohm input impedance on an amp). What would be the effect on the F5's performance of doing this?
2) Could one use paper-in-oil caps in the power supply? I know a diy'er who swears by them, even in the power supply, for imparting a rich, full, warm sound.
Thanks.
f5 amp
its the fairchild set that increases the output ,I mentioned that for the sake of completness.whether that is material is moot, I should mentionwhen I put a cap on the front the output goes to zero. Even so I am still not satisfied and will investgate further
its the fairchild set that increases the output ,I mentioned that for the sake of completness.whether that is material is moot, I should mentionwhen I put a cap on the front the output goes to zero. Even so I am still not satisfied and will investgate further
TH1 & 2
Could someone please confirm if these are the correct thermistors that are to be placed in series with R15 & R16.
http://newzealand.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=1912257
Regards
Brett
Could someone please confirm if these are the correct thermistors that are to be placed in series with R15 & R16.
http://newzealand.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=1912257
Regards
Brett
I have also found a site for the following. Which has a minimum order of 20.
http://www.ampslab.com/trans_2sj74bl.htm
What I'll do with 40 of these, but if that's what it takes to get this amp built.
Sorry for asking so many questions, but I'd rather check with someone who know's more than I do.
http://www.ampslab.com/trans_2sj74bl.htm
What I'll do with 40 of these, but if that's what it takes to get this amp built.
Sorry for asking so many questions, but I'd rather check with someone who know's more than I do.
Brett,
if you are only after 2 pairs of J74/K170 you could ask if someone has some spares for you.
PayaPalling a few dollars is easier on the wallet than shelling out $40 and be stuck with $36 in parts you don't have a destination for.
Maybe you should ask the right question.
if you are only after 2 pairs of J74/K170 you could ask if someone has some spares for you.
PayaPalling a few dollars is easier on the wallet than shelling out $40 and be stuck with $36 in parts you don't have a destination for.
Maybe you should ask the right question.
Quite right
I have purchased a couple of chips from here before, and just happened to go back to have another look. I found a good deal on some parts for the F5.
http://tech-diy.com/inside_tech_diy.htm
I couldn't get get these here for this price and matched as well great stuff........
😀
Brett.
I have purchased a couple of chips from here before, and just happened to go back to have another look. I found a good deal on some parts for the F5.
http://tech-diy.com/inside_tech_diy.htm
I couldn't get get these here for this price and matched as well great stuff........
😀
Brett.
ChuckE,
You might consider building the supply on the last page of the F5's operating manual.
http://www.firstwatt.com/downloads/F5-om_sm-080527.pdf
If you go to www.apexjr.com you can get 12,000uf caps for 1.99 each. The PIO caps will NEVER have enough capacitance to work well in the power supply for this amp unless they are the size of a broom closet. You could use them to snubber the supply though.
Uriah
You might consider building the supply on the last page of the F5's operating manual.
http://www.firstwatt.com/downloads/F5-om_sm-080527.pdf
If you go to www.apexjr.com you can get 12,000uf caps for 1.99 each. The PIO caps will NEVER have enough capacitance to work well in the power supply for this amp unless they are the size of a broom closet. You could use them to snubber the supply though.
Uriah
Brett,
I had similar questions about TH1 and TH2. From the answers I received I think that the thermistor you found will work fine. It seems that the wattage it is capable of really doesnt matter much and you are at 4.7k so that should work fine. I have mine 90% built for some reason and not 100% so I cant say that mine fired right up no problem yet. However, I could also add that Nelson says in his paper on the F5 that the Thermistor is not necessary and a few people have left it out of their amp, replaced by a resistor. So I think you can count yourself safe with that Thermistor.
Uriah
I had similar questions about TH1 and TH2. From the answers I received I think that the thermistor you found will work fine. It seems that the wattage it is capable of really doesnt matter much and you are at 4.7k so that should work fine. I have mine 90% built for some reason and not 100% so I cant say that mine fired right up no problem yet. However, I could also add that Nelson says in his paper on the F5 that the Thermistor is not necessary and a few people have left it out of their amp, replaced by a resistor. So I think you can count yourself safe with that Thermistor.
Uriah