tag:blogger.com,1999:blog-36956433.post9105657932334567115..comments2024-02-08T06:47:40.662-06:00Comments on DIY Audio Projects - Hi-Fi Blog for DIY Audiophiles: Ultra-Linear 6T9 DIY Tube AmplifierdiyAudioProjects.comhttp://www.blogger.com/profile/02982731963250878024noreply@blogger.comBlogger20125tag:blogger.com,1999:blog-36956433.post-58527612043199104582020-10-14T20:34:02.933-05:002020-10-14T20:34:02.933-05:00I’m ready to build this amp but I’d like to use tu...I’m ready to build this amp but I’d like to use tube rectification. I have a strong 5u4 tube that I’d like to incorporate into the build. Anyone try tube rectification for this amp?Peskycathttps://www.blogger.com/profile/10809334020804297536noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-77881715894839902712019-04-27T19:39:16.900-05:002019-04-27T19:39:16.900-05:00I bought one of these off eBay. I added a choke, p...I bought one of these off eBay. I added a choke, put mundorf Evo oil coupling caps and the UL upgrade as well. Sounded pretty good, then I put jumpers in place of the input caps. The difference was astounding. The cymbals sound as though they were in the room. Got rid of the "muddy and dark" sound. Highs really sparkle, just crisp and clean. I am running a preamp so DC in the inputs are a non-issue. Thanks for the info.higgsbozonhttps://www.blogger.com/profile/17160125683291778336noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-43698583024875951132017-09-19T08:35:36.982-05:002017-09-19T08:35:36.982-05:00Could you clarify the use of the 0.1uF caps across...Could you clarify the use of the 0.1uF caps across the PSU caps? I do this for all kit with RF floating about, but don't understand the benefit for audio equipment. Thanks.Janhttps://www.blogger.com/profile/01300598119430328669noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-4570433417827764442017-05-18T23:10:05.623-05:002017-05-18T23:10:05.623-05:00Anon
it really does not matter what PT you use or...Anon<br /><br />it really does not matter what PT you use or manufacture. Use a PT in the range of 300-300 HT and 6.3v at 2a for the heaters. Use solid state rectifiers like the 1n4007, either in a full wave and full wave center tap config. In a full wave bridge config use the listed Caps for values. In a Centertap config use a larger cap config by 20%. But these 6T9 tubes don't req., very much current. At max vol expect 60-80ma current. So even a secondhand PT would be fine. vincevincehttps://www.blogger.com/profile/09280325690588537402noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-73138194631010348022017-05-18T23:01:05.823-05:002017-05-18T23:01:05.823-05:00Jim
it sounds like you need to contact Edcor and a...Jim<br />it sounds like you need to contact Edcor and ask for technical support. It's not the DIY amp here that is blowing your fuses. I think it's the Edcor transformer and use slowblow fuses. vincevincehttps://www.blogger.com/profile/09280325690588537402noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-12120466871325148212017-05-18T22:55:24.422-05:002017-05-18T22:55:24.422-05:00Ooops Undelivered(user not known)i mean(typo) and ...Ooops Undelivered(user not known)i mean(typo) and was returned back to me. Any-help in this matter would be most greatly appreciated. Vince vincehttps://www.blogger.com/profile/09280325690588537402noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-72086397806805024452017-05-18T22:53:18.891-05:002017-05-18T22:53:18.891-05:00I have tried just now to Email the author of this ...I have tried just now to Email the author of this project and i am unable to contact him (email was returned deliverable). If i could get the pictures of the Schematic and power supply schematic that would be very helpful because they come up here on this page and blank images! Vincevincehttps://www.blogger.com/profile/09280325690588537402noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-56783643935061429232017-05-18T22:42:29.055-05:002017-05-18T22:42:29.055-05:00I don't quite understand UL configurations fro...I don't quite understand UL configurations from Pentode configs. vince vincehttps://www.blogger.com/profile/09280325690588537402noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-78591751871647511932017-05-18T22:41:08.877-05:002017-05-18T22:41:08.877-05:00I wish there was a parts list or BOM. The posted p...I wish there was a parts list or BOM. The posted pictures here on these web pages don't show and shows just a blank image. vincevincehttps://www.blogger.com/profile/09280325690588537402noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-37433230371878062372017-05-18T22:39:08.063-05:002017-05-18T22:39:08.063-05:00http://www.ebay.com/itm/6T9-GE-USA-Compactron-New-...http://www.ebay.com/itm/6T9-GE-USA-Compactron-New-Old-Stock-Tested-BIN-15-/222513992624? for your 6T9 tubes.vincehttps://www.blogger.com/profile/09280325690588537402noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-78443594574060130892016-11-16T05:22:55.747-06:002016-11-16T05:22:55.747-06:00http://www.thetubestore.com/ For your 6T9 tubes.http://www.thetubestore.com/ For your 6T9 tubes.Divalihttps://www.blogger.com/profile/09299224980407539090noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-36946241822411076912013-02-07T22:18:39.319-06:002013-02-07T22:18:39.319-06:00Hi Jim, try using a slow blow fuse.
CheersHi Jim, try using a slow blow fuse.<br /><br />CheersGiohttps://www.blogger.com/profile/15071197125706845843noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-72648732045186653062013-01-31T13:58:15.389-06:002013-01-31T13:58:15.389-06:00I built this amp, and when it works it sounds very...I built this amp, and when it works it sounds very nice. However, I do have an issue. It eats fuses like candy. The only deviation i made from the schematic was for the power transformer. I used an Edcor XPWR065-120 for the power transformer. It has the same voltage IO, but higher current capability. I assumed (maybe incorrectly) that since the output xfrmr voltages were the same, then the current would be dictated by the circuit connected and not related to the xfrmr itself. Anyway, I've used even 5A fuses and even they blow (usually at turn on).<br /><br />Any help would be appreciated... info or even the best way to debug the issue.<br /><br />Thanks,<br />JimJimhttps://www.blogger.com/profile/08387775712305341928noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-84970843778541566942012-05-08T12:35:47.955-05:002012-05-08T12:35:47.955-05:00Hi Jim,
Based on your description, you may have a...Hi Jim,<br /><br />Based on your description, you may have a heat build up problem. As the temp rises, the resistors will change in value and that could be the source of your problems.<br /><br />I would suggest by improving ventilation through the chassis. Drill holes in the top plate to exhaust the heat and holes in the bottom to take in fresh are.<br /><br />Hope this helps.Giohttps://www.blogger.com/profile/15071197125706845843noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-86699177208786865352012-05-04T14:40:06.365-05:002012-05-04T14:40:06.365-05:00I built this project and it sounds much better tha...I built this project and it sounds much better than I expected... very musical and crisp, yet mellow.<br /><br />I do have one comment and two questions:<br /><br />Comment: Using diodes to make the rectifier, the turn-on current is high enough to blow 0.75A slo fuses... I moved to 1.0A and all is fine.<br /><br />Question1: The metal chassis near the tubes get hot... like real hot. Hot enough to melt the epoxy I used to glue some spacers inside the chassis. Is that expected? Is there better glue to use?<br /><br />Question2: After an hour or so of use (first time) the gain seemed to decrease and a hissing noise seemed to increase over time. I assume related to the heat... as I turned it off, and later it sounded fine.Jimhttps://www.blogger.com/profile/08387775712305341928noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-85198930633986556022011-07-16T12:18:44.949-05:002011-07-16T12:18:44.949-05:00It looks like the same power transformer from the ...It looks like the same power transformer from the other 6T9 project build: http://diyaudioprojects.com/Tubes/6T9-Tube-Amp-Kit/<br /><br />"I used a Hammond 369JX power transformer and Edcor XSE15-8-5K for the output transformers (OT)"Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-36956433.post-76825814621505696302011-07-08T10:15:30.327-05:002011-07-08T10:15:30.327-05:00What make/model xformer was used in the power supp...What make/model xformer was used in the power supply?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-36956433.post-79211146471281801522011-04-18T15:57:54.097-05:002011-04-18T15:57:54.097-05:00Power calculation must use RMS voltage...(6.2Vp-p ...Power calculation must use RMS voltage...(6.2Vp-p / 2) * .707Anonymoushttps://www.blogger.com/profile/17167656751179357448noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-61136489208981419362011-04-06T23:31:43.468-05:002011-04-06T23:31:43.468-05:004.5 Watts you mean, right? Power = Voltage x Vol...4.5 Watts you mean, right? Power = Voltage x Voltage / Resistance.wliphttps://www.blogger.com/profile/11984897750882196119noreply@blogger.comtag:blogger.com,1999:blog-36956433.post-30048715827760709832009-03-31T20:36:00.000-05:002009-03-31T20:36:00.000-05:00You show a 6.2Vp-p output into an 8ohm load. This ...You show a 6.2Vp-p output into an 8ohm load. This is approximately 600mW into the load. I am assuming that this isn't full power. Do you have any estimates of maximum clean output power and input sensitivity for this UL version?Anonymousnoreply@blogger.com