Search found 15 matches
- 22 Dec 2018, 13:38
- Forum: Vintage Stompbox Corner ( ... - 1975)
- Topic: Tonebender MkI More Bass
- Replies: 8
- Views: 3112
Re: Tonebender MkI More Bass
I hope you've checked your 10uf cap polarity before placing it :) Yep - +ve towards Q3 base :) Hmmmmm.....that is the way it is drawn in the Hurst schematic, however I have just measured across the cap and it is definitely +6v on the Q2 collector side Vs +0.5v on the Q3 base side. I have made sure ...
- 22 Dec 2018, 10:32
- Forum: Vintage Stompbox Corner ( ... - 1975)
- Topic: Tonebender MkI More Bass
- Replies: 8
- Views: 3112
Re: Tonebender MkI More Bass
I hope you've checked your 10uf cap polarity before placing it :) Yep - +ve towards Q3 base :) Hmmmmm.....that is the way it is drawn in the Hurst schematic, however I have just measured across the cap and it is definitely +6v on the Q2 collector side Vs +0.5v on the Q3 base side. I have made sure ...
- 21 Dec 2018, 15:18
- Forum: Vintage Stompbox Corner ( ... - 1975)
- Topic: Tonebender MkI More Bass
- Replies: 8
- Views: 3112
Re: Tonebender MkI More Bass
Yep - +ve towards Q3 baseplush wrote:I hope you've checked your 10uf cap polarity before placing it
- 21 Dec 2018, 12:34
- Forum: Vintage Stompbox Corner ( ... - 1975)
- Topic: Tonebender MkI More Bass
- Replies: 8
- Views: 3112
Re: Tonebender MkI More Bass
that has this at 25uF electro Going higher than 1-2uf already makes no sense to me. 25 uf seems more like аll original leftover brought to us by retarded boutique builders. lol ! But I get your drift! Just tried some caps out - anything more than the 0.1uF does add more bass progressively. 1uF seem...
- 21 Dec 2018, 10:11
- Forum: Vintage Stompbox Corner ( ... - 1975)
- Topic: Tonebender MkI More Bass
- Replies: 8
- Views: 3112
Re: Tonebender MkI More Bass
Have a Tonebender MkI that currently has standard cap values in, from input to output: 0.01uF input 25uF between Q1 and Q2 0.1uF between Q2 and Q3 0.1uF Output Although it probably is a "true" TB MkI sound, it is a little thin for me - what is the easiest way to get more bass from it ? Do...
- 21 Dec 2018, 09:27
- Forum: Vintage Stompbox Corner ( ... - 1975)
- Topic: Tonebender MkI More Bass
- Replies: 8
- Views: 3112
Tonebender MkI More Bass
Have a Tonebender MkI that currently has standard cap values in, from input to output: 0.01uF input 25uF between Q1 and Q2 0.1uF between Q2 and Q3 0.1uF Output Although it probably is a "true" TB MkI sound, it is a little thin for me - what is the easiest way to get more bass from it ? Do ...
- 17 Dec 2018, 11:29
- Forum: Vintage Stompbox Corner ( ... - 1975)
- Topic: Colorsound - Power Boost / Overdriver
- Replies: 188
- Views: 149774
Re: Colorsound - Power Boost / Overdriver
I did another layout for the CSOD, and I forgot to share it here! Super easy build. Board-mounted pots w/ gain control, made to fit very comfortably in a 1590BB. [ Image ] [ Image ] Here are the ExpressPCB pcb/sch files and PDF toner transfer: http://www.justonemorebuild.com/project-colorsound-over...
- 02 Apr 2015, 22:03
- Forum: Printed/Published Online Designs
- Topic: BC109 HFE
- Replies: 19
- Views: 10372
Re: BC109 HFE
Many many thanks guys.
One last thought - is the highest hFE tranny best placed in one of the the positions?
My guess would be lower ones in Q1 and Q2 with the larger at Q3.
I will socket and see anyway.
One last thought - is the highest hFE tranny best placed in one of the the positions?
My guess would be lower ones in Q1 and Q2 with the larger at Q3.
I will socket and see anyway.
- 02 Apr 2015, 19:56
- Forum: Printed/Published Online Designs
- Topic: BC109 HFE
- Replies: 19
- Views: 10372
Re: BC109 HFE
Hi grrrunge, its is the guitarpcb DSOTM fuzz based on the Lunar Module. I noted in one of the threads when theLM was traced, regarding the HFE of the BC109C required. In the past hour I just set up an RG Keen test circuit ( not exact same R's but close to work through the maths Rb 2.047MO Rc2.49kO, ...
- 02 Apr 2015, 17:30
- Forum: Printed/Published Online Designs
- Topic: BC109 HFE
- Replies: 19
- Views: 10372
Re: BC109 HFE
OK, couple of clarifications. Yes, the fact sheet PDFs show it is Ic in mA not the base current, my bad. Also, the RG Keen article works at around 4uA base current, not 1uA from what is written there I think. Done lots of testing this afternoon and managed to mangle 2 of my Bc109's already somehow :...
- 02 Apr 2015, 16:09
- Forum: Printed/Published Online Designs
- Topic: BC109 HFE
- Replies: 19
- Views: 10372
Re: BC109 HFE
I think R.G. Keen uses a figure of 1uA Base current (one microamp) for his Transistor current-gain measuring circuit article.... Ok, sort of following so far....so if I test my BC109C with RG Keen's setup - based on 1uA Base current (2.2MO and and 2.47KO Res), then what is the corresponding hFE fig...
- 02 Apr 2015, 11:55
- Forum: Printed/Published Online Designs
- Topic: BC109 HFE
- Replies: 19
- Views: 10372
Re: BC109 HFE
Testing a number of my old BC109Cs on my DCA 55 show gains in the 500s with a test collector current of 2.5mA. Ah - ok, think I am getting somewhere - I need to be able to test at "mA" levels, and not "uA" levels to get those >500 figures, and my DMM tests at 10uA! Not sure - bu...
- 02 Apr 2015, 11:07
- Forum: Printed/Published Online Designs
- Topic: BC109 HFE
- Replies: 19
- Views: 10372
Re: BC109 HFE
Hi DrNomis -indeed, the bits I quote re the hfe (HFE) values are from the pdf factsheets for BC109C's hence my confusion about what is being measured. In the RG Keen article, and my DMM, and they do both seem to be measuring DC at uA ranges, which equate to 260-270 in the pdf. So where are the >500 ...
- 02 Apr 2015, 08:19
- Forum: Printed/Published Online Designs
- Topic: BC109 HFE
- Replies: 19
- Views: 10372
Re: BC109 HFE
Thanks - more surfing last night showed that most of the test circuits are DC based, with a 9v battery small resistors (xk and xM ranges) leading to micro-amp currents. So this matches the DMM setup at "10ua and Vce 2.5v" - spot on values of 250-260 vs the pdf. So I can't believe that ther...
- 01 Apr 2015, 14:03
- Forum: Printed/Published Online Designs
- Topic: BC109 HFE
- Replies: 19
- Views: 10372
BC109 HFE
Hi - long time lurker, first post, so be gentle ;) I've read a lot abot how the hfe of a transistor may be important to know (depends on usage), so bought a multimeter (Uni-Trend UT132A) to do just that - tell me the hfe of a set of BC109C's I have. Note: These are Silicon, not germanium hence the r...