Members sunntone Posted April 12, 2009 Members Share Posted April 12, 2009 So I replaced the output transformer with a Hammond 125b, giving me just a wee bit more clean headroom and adding the TONE to the drive channel. In addition I replaced the stock power tube (EH 12ax7) with a Mullard. The two upgrades have really helped to make the drive channel more articulate and the gain to be less saturated but more driven and smooth. I highly recommend these upgrades for the ht-5 head. Two things to note:1) you will still have to connect the center tap (red wire) from the hammond to the board at position SP6 on the main board (this is where you'll already have removed the center tap lead from the stock OT. Hammond says that since the OT is made for both single ended and A/B(push pull) operation that this center tap can be taped off in a single ended application. I found that this is not the case and the amp will only produce sound with the center tap connected. 2) You will have to drill a new output jack hole for the new OT, as the stock jack connector lug will not receive the secondary leads from the OT, these leads are not defined which is + and - you can put them at either lug on the speaker and it will work OK. I simply put in a new jack and set the leads for an 8 ohm output and voila we have a much improved amp! I will try to post some pics later if anyone wants to see them cheers Link to comment Share on other sites More sharing options...
Members Neilrocks25 Posted April 12, 2009 Members Share Posted April 12, 2009 interesting.I would like to see this oh and Clips or you turned it into a bugera Link to comment Share on other sites More sharing options...
Members sunntone Posted April 12, 2009 Author Members Share Posted April 12, 2009 here is a pic. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted April 12, 2009 Members Share Posted April 12, 2009 The only mod I really want is to keep the speakers alive when using the line-out. Is the circuit as simple as being a switched jack on the line-out that cuts the speaker? Link to comment Share on other sites More sharing options...
Members sunntone Posted April 12, 2009 Author Members Share Posted April 12, 2009 The only mod I really want is to keep the speakers alive when using the line-out. Is the circuit as simple as being a switched jack on the line-out that cuts the speaker? yeah I am thinking about this one... why do you want this though just so I can understand better. You want to be able to use the emulated line out while also having the speakers active? I actually don't know off hand, I would have to check that out. I'm telling you the upgraded transformer made a huge improvement - no more crackle at all. Super smooth drive and sonically it seems to respond even better to my OD and boost pedals now. The Mullard also is a positive. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted April 12, 2009 Members Share Posted April 12, 2009 yeah I am thinking about this one... why do you want this though just so I can understand better. You want to be able to use the emulated line out while also having the speakers active? I actually don't know off hand, I would have to check that out. I'm telling you the upgraded transformer made a huge improvement - no more crackle at all. Super smooth drive and sonically it seems to respond even better to my OD and boost pedals now. The Mullard also is a positive. I pit a Tungsol in mine. Also tried a 9th gen Chinese. Ya, I use mine live and would prefer to skip the mic if the line out is as good as everyone says. Link to comment Share on other sites More sharing options...
Members sunntone Posted April 12, 2009 Author Members Share Posted April 12, 2009 I pit a Tungsol in mine. Also tried a 9th gen Chinese. Ya, I use mine live and would prefer to skip the mic if the line out is as good as everyone says. I've left the stock pre-amp, I'll have to order a 12BU7 (yes I am going to use the BU7 instead) I only changed the power tube. I just looked at it again I and believe you will not do this w/o an amp tech, the switch is soldered to the board so that when you plug in the line out it will cut out the speaker jacks. Since the jacks are soldered to the PCB you will not be able to easily remove them. An amp tech may be able to do this for you though. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted April 12, 2009 Members Share Posted April 12, 2009 I've left the stock pre-amp, I'll have to order a 12BU7 (yes I am going to use the BU7 instead) I only changed the power tube.I just looked at it again I and believe you will not do this w/o an amp tech, the switch is soldered to the board so that when you plug in the line out it will cut out the speaker jacks. Since the jacks are soldered to the PCB you will not be able to easily remove them. An amp tech may be able to do this for you though. thanks for looking. Link to comment Share on other sites More sharing options...
Members sunntone Posted April 12, 2009 Author Members Share Posted April 12, 2009 happy to can't believe no one else is interested in this really cheap and amazing mod... i thought there was a huge ht-5 contingent on this board? Link to comment Share on other sites More sharing options...
Members NeloAngelo Posted April 12, 2009 Members Share Posted April 12, 2009 can't believe no one else is interested in this really cheap and amazing mod... i thought there was a huge ht-5 contingent on this board? probably all still waiting to get their preorders filled lol. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted April 12, 2009 Members Share Posted April 12, 2009 happy to can't believe no one else is interested in this really cheap and amazing mod... i thought there was a huge ht-5 contingent on this board? Well, I'm pretty happy with mine as is. But always curious. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted April 12, 2009 Members Share Posted April 12, 2009 If there was one mod I could put in mine it would be a single tone control circuit like what the Crate V58/V8 has on the clean channel. Link to comment Share on other sites More sharing options...
Members -todgemistro- Posted April 13, 2009 Members Share Posted April 13, 2009 If I wanted to change anything with mine I would get rid of the clean channel all together and have reverb, using the clean channel knob as a reverb control instead Link to comment Share on other sites More sharing options...
Members mcr23 Posted April 13, 2009 Members Share Posted April 13, 2009 Clips or you turned it into a bugera :lol: Bugera bashing is always win Link to comment Share on other sites More sharing options...
Members VanR Posted April 13, 2009 Members Share Posted April 13, 2009 You have to use the red center tap on the Hammond because the HT-5 is a push/pull amp. Not single ended. Link to comment Share on other sites More sharing options...
Members sunntone Posted April 13, 2009 Author Members Share Posted April 13, 2009 You have to use the red center tap on the Hammond because the HT-5 is a push/pull amp. Not single ended. can you cite this statement? It uses a 12BH7 in the pre amp which is typically a push pull but this does not make it a A/B class? Link to comment Share on other sites More sharing options...
Members mystixboi1 Posted April 13, 2009 Members Share Posted April 13, 2009 very cool. i have one of these on the way. i keep hearing that the clean channel needs more headroom. i would love to hear comparison clips Link to comment Share on other sites More sharing options...
Members tlbonehead Posted April 13, 2009 Members Share Posted April 13, 2009 can you cite this statement? It uses a 12BH7 in the pre amp which is typically a push pull but this does not make it a A/B class? aren't you the one who did the mod? that tube is the power tube, operating in a push-pull arrangement on the two sides of the tube. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted April 13, 2009 Members Share Posted April 13, 2009 very cool. i have one of these on the way. i keep hearing that the clean channel needs more headroom. i would love to hear comparison clips Well, its a 5 watt amp and as loud or louder than most of the others out there. If more clean headroom is needed, this probably isn't the amp to get. Link to comment Share on other sites More sharing options...
Members Hawkeye17 Posted April 13, 2009 Members Share Posted April 13, 2009 I've left the stock pre-amp, I'll have to order a 12BU7 (yes I am going to use the BU7 instead) I only changed the power tube.I just looked at it again I and believe you will not do this w/o an amp tech, the switch is soldered to the board so that when you plug in the line out it will cut out the speaker jacks. Since the jacks are soldered to the PCB you will not be able to easily remove them. An amp tech may be able to do this for you though. The EH 12BU7 isn't too bad really. I got a NOS Sylvania 12BU7 and didn't notice a change in tone between the two and the Sylvania is very well reviewed for NOS 12BU7's. Changing the Sovtek 12AX7 is a must..that tube blows. I dropped an old Mullard into mine and it makes the amp. I tried JJs, 9th Gen chinese, Tung Sol, reissue Mullard and a NOS Tesal(not the JJ ones) in mine and they all sounded way better than that Sovtek. The Mullard and 9th Gen Chinese sounded the best of the bunch to my ears but they all had their own flavor and this amp brings out the differences in tone between them quite a bit. Link to comment Share on other sites More sharing options...
Members sunntone Posted April 13, 2009 Author Members Share Posted April 13, 2009 aren't you the one who did the mod? that tube is the power tube, operating in a push-pull arrangement on the two sides of the tube. yes i did. and you're right which means I overlooked the importance of the 12BU7 for the the sound, thinking it was the pre amp, oops Link to comment Share on other sites More sharing options...
Members sunntone Posted April 13, 2009 Author Members Share Posted April 13, 2009 Well, its a 5 watt amp and as loud or louder than most of the others out there. If more clean headroom is needed, this probably isn't the amp to get. I have tons more clean headroom now with this upgrade. On clean channel I can turn the volume up to 2 o'clock and it's even a little chimey Link to comment Share on other sites More sharing options...
Members tlbonehead Posted April 13, 2009 Members Share Posted April 13, 2009 I have tons more clean headroom now with this upgrade. On clean channel I can turn the volume up to 2 o'clock and it's even a little chimey Mine doesn't started compressing much until after about 7-8 on the dial, and it is indeed a Voxy chime in that area. Link to comment Share on other sites More sharing options...
Members sunntone Posted April 13, 2009 Author Members Share Posted April 13, 2009 just tested it again, and I can turn the clean volume FULL up with no compression or distortion. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted April 13, 2009 Members Share Posted April 13, 2009 just tested it again, and I can turn the clean volume FULL up with no compression or distortion. Good for some people here but not a mod that I would want. Link to comment Share on other sites More sharing options...
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