Thanks for the links, but it's about the TG6556, used on Hiwatt DR504. Or did I miss something ?...trobbins wrote: ↑Mon Jun 03, 2019 7:02 am TG9686 detailed info in linked thread:
https://groupdiy.com/index.php?topic=72605.0
https://groupdiy.com/index.php?topic=72609.0
Search found 55 matches
- Mon Jun 03, 2019 1:39 pm
- Forum: Technical Discussion
- Topic: Partridge transformers specifications ?
- Replies: 11
- Views: 1982
Re: Partridge transformers specifications ?
- Sun Jun 02, 2019 12:54 pm
- Forum: Technical Discussion
- Topic: Partridge transformers specifications ?
- Replies: 11
- Views: 1982
Re: Partridge transformers specifications ?
Output Transformer is Raa of 4K to suit a pair of EL34 according to this: https://picclick.fr/PARTRIDGE-output-transformer-50-Watts-4k-Ohm-123290414878.html Cheers, Ian Thanks Ian, and thanks to you all. I found the tests result, but as you stated trobbins, I'm a bit puzzled with the measurements. ...
- Mon May 20, 2019 5:18 pm
- Forum: Technical Discussion
- Topic: Partridge transformers specifications ?
- Replies: 11
- Views: 1982
Partridge transformers specifications ?
Hello, I'm looking for the specs of some Partridge transformers. I have a set of PT, OT and choke from a Dan Armstrong 60 head, but I can't find anything about them. PT is TH2025. OT is TG9686. Choke is TH9688. I'm ok with the PT (2x440VAC, 2x3.15VAC), but I'd like to know the primary impedance of t...
- Wed Dec 05, 2018 10:48 am
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss/oscillation on the OD channel of an ODS
Thank you all for your replies and advices. Those heater wires are running parallel with the OD wires. I would try lifting them up and see if that makes any difference, or try shielded wire. Thanks Aaron, the wires next to the heaters are not signal but B+ wires. But it could also cause some noise, ...
- Mon Dec 03, 2018 11:01 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss/oscillation on the OD channel of an ODS
Swapping the OT primaries should result in a big squeal or no squeal. So it's uncertain what you actually did. :shock: :shock: :shock: :shock: ???????????? Forget this OT, pleeaaase... I buid amps for 20 years, so I know this problem of OT leads. Yes it produces a big squeal if it's wired incorrect...
- Mon Dec 03, 2018 8:43 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss/oscillation on the OD channel of an ODS
If you said that swapping OT had no impact then that's not right either because if you had it right and swapped there'd be a very clear impact Of course swapping the leads has an impact, but it did not solved my problem. And yes, I will try to make a sound sample. I want to show you a small example...
- Mon Dec 03, 2018 1:59 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
- Mon Dec 03, 2018 1:54 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
- Mon Dec 03, 2018 1:45 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss/oscillation on the OD channel of an ODS
If you dont know where the oscillation is coming from how would you identify if its coming from the OT or not? Based on new information I also believe this is the commonest problem ever to happen on any amp with some NFB. Disco the NFB. Swap the darned OT wires and hook the NFB back up where it was...
- Sun Dec 02, 2018 11:14 am
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss/oscillation on the OD channel of an ODS
I do not think the author is talking about the natural hissing of the tubes. Most likely, this is some kind of positive feedback between the stages. Yes, that's it ! :) Thanks. It's a feedback, not from the OT, but I don't understand where that comes from. I did all the things you mention : swappin...
- Wed Nov 28, 2018 8:10 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss/oscillation on the OD channel of an ODS
Big oscillations are often caused by a bad lead dress. Find the #124 pics on http://thesubjectmatter.com/dumblearchive.html and compare your wiring to what Mr Dumble did on his. Yes you're right. I also did some changings in the wirings. In fact I use this OD schematic for years, and now I use very...
- Wed Nov 28, 2018 7:51 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss on the OD channel of an ODS
Play guitar through the amp. First stage aroung 4. Tone controls moderated, OD controls OD gain around 6-7 and OD volume to match clean volume (arond 3-4) . Master on 5. That is how these amps are supposed to be used. Cranking every control is like flooring the gas in yiur car and sayint the car is...
- Wed Nov 28, 2018 7:18 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss on the OD channel of an ODS
Yes, I tried it too. Not a big influence...Bombacaototal wrote: ↑Wed Nov 28, 2018 3:31 pmI would think that the correct outside foil orientation of the caps might help?
- Wed Nov 28, 2018 7:17 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss on the OD channel of an ODS
There is a direct relationship between gain and noise(hiss). As gain increases noise also increases. No way around that fact. tube amps hiss on high volume/gain. if you ever stood in front of Brian May's 6 AC30's you wouldn't believe the hiss that comes from them just sat there. Once everyone start...
- Wed Nov 28, 2018 2:43 pm
- Forum: Dumble Discussion
- Topic: Hiss/oscillation on the OD channel of an ODS
- Replies: 37
- Views: 3452
Re: Hiss on the OD channel of an ODS
Yes, I also swapped different tubes. Some are quieter indeed, but the hiss still comes with high gain and volume.martin manning wrote: ↑Wed Nov 28, 2018 2:10 pm Have you tried screening for low noise tubes, especially in V1?